Liquid crystal display device with two capacitive electrode layers in specific locations

ABSTRACT

Image display device having an electrode forming layer which includes a plurality of gate lines, a plurality of drain lines, a plurality of switching elements and the a plurality of pixel electrodes,
         and having reference electrode layer between the electrode forming layer and a substrate where the electrode forming layer formed thereon, and the reference electrode layer and the electrode forming layer are insulated by insulating layer.

This application is a Divisional of U.S. Ser. No. 10/237,911 filed Sep.10, 2002 now U.S. Pat. No. 6,970,222. Priority is claimed based on U.S.Ser. No. 10/237,911 filed Sep. 10, 2002, which claims priority toJapanese Patent Application No. 2001-317147 filed on Oct. 15, 2001, andwhich is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a liquid crystal display device, andmore particularly to an active matrix type liquid crystal display devicewhich can reduce holding capacity for holding lighting of pixels for agiven time and feeding resistance thereof thus enhancing numericalaperture.

2. Description of the Related Art

An active matrix type liquid crystal display device generally adopts asystem in which liquid crystal is sandwiched between a pair ofsubstrates which face each other in an opposed manner and pixels areselected by pixel electrodes which are driven by a large number ofswitching elements represented by thin film transistors formed on one ofthe above-mentioned pair of substrates. One type of the liquid crystaldisplay device adopting such a system is a so-called vertical field typein which on the other substrate (second substrate) which faces onesubstrate (first substrate) of the above-mentioned pair of substrates,color filters and common electrodes are formed or the color filters arealso formed on the first substrate.

As another system, there exists a so-called IPS system in which counterelectrodes which correspond to the common electrodes are formed on theabove-mentioned first substrate side. Also with respect to this system,there has been known a system which forms color filters on either thefirst substrate side or the second substrate side.

The vertical field type liquid crystal display device includes aplurality of gate lines which extend in the first direction (usuallyhorizontal scanning direction) and are arranged parallel to each otherand a plurality of drain lines which extend in the second directionwhich crosses the gate lines (usually vertical scanning direction) andare arranged parallel to each other. The liquid crystal display devicefurther includes switching elements such as thin film transistors or thelike in the vicinity of respective crossing portions of the gate linesand drain lines and pixel electrodes which are driven by the switchingelements.

In this vertical field type liquid crystal display device, the commonelectrodes are formed on the second substrate such that the commonelectrodes face the pixel electrodes in an opposed manner, an electricfield is generated between the common electrodes and the selected pixelelectrodes in the direction which approximately crosses a surface of thesubstrate at a right angle, and lighting of the pixels is performed bychanging the orientation of liquid crystal molecules sandwiched betweenthe pixel electrode and the common electrodes.

On the other hand, in the IPS type liquid crystal display device, gatelines, drain lines, and switching elements similar to those of thevertical field type liquid crystal display device are formed on an innersurface of the above-mentioned first substrate, comb-shaped pixelelectrodes are formed on the same substrate, and counter electrodes areformed close to the pixel electrodes on the same substrate. Then, anelectric field is generated between the selected pixel electrodes andthe counter electrodes in the direction approximately parallel to asurface of the substrate, and lighting of the pixels is performed bychanging the orientation direction of liquid crystal molecules arrangedbetween the pixel electrodes and the counter electrodes. As a liquidcrystal display device which has developed this type, there exists aliquid crystal display device which adopts a matted electrode as thecounter electrodes and forms comb-shaped pixel electrodes as a layerabove or below the counter electrodes.

In both of the above-mentioned type liquid crystal display devices, thecharge storing capacity for holding the lighting time of the pixelswhich are lit due to selection at a given value (hereinafter, simplyreferred to as “holding capacity”) is formed in regions where the pixelelectrodes and the gate lines are overlapped or regions where otherelectrode lines which are formed such that the other electrode linestransverse the pixel electrode forming region and the pixel electrodes,and feeding paths for storing charge in the holding capacity is formedof either the gate lines or the above-mentioned electrode lines.

SUMMARY OF INVENTION

In this manner, one electrode which forms the holding capacity is alinear electrode and the feeding is limited to one direction (extendingdirection of the electrode) and hence, the feeding resistance is large.Further, corresponding to the increase of the distance between theelectrode and a feeding end, the voltage drop is remarkably increased sothat there arises a case that the required charge cannot be fed.Further, since the above-mentioned gate line usually crosses the drainline, a crossing capacity is increased. As a result, this has been oneof causes which make the rapid driving of liquid crystal display devicedifficult. As a countermeasure to cope with such a problem, there hasbeen proposed a liquid crystal display device which uses theabove-mentioned other electrode line. However, when the holding capacityis formed in the pixel electrode forming region, numerical aperture isreduced as a matter of course.

Further, along with the demand for high definition, the size of pixelsper one pixel is reduced so that there has been a task that it isdifficult to form the sufficient holding capacity.

Further, although it is effective to reduce the size of the holdingcapacity to enhance the numerical aperture, this brings about thereduction of the holding capacity. That is, there has been a task thatthere exists a trade-off relationship between the enhancement ofnumerical aperture and the assurance of holding capacity.

Accordingly, it is an object of the present invention to provide anactive matrix liquid crystal display device which can reduce resistanceof feeding electrodes which constitute holding capacities. It is anotherobject of the present invention to provide a rapid driving active matrixtype liquid crystal display device having high brightness by obviatingthe reduction of numerical aperture of pixels.

It is still another object of the present invention to realize an activematrix type liquid crystal display device which can satisfy both of theassurance of holding capacity and the enhancement of numerical aperturesimultaneously.

Other objects and advantages of the present invention will be apparentfrom the explanation made hereinafter.

The typical constitution of the present invention lies in that on aswitching element forming substrate of the liquid crystal displaydevice, a transparent conductive layer (reference layer) having a largearea which covers at least a major portion or a whole area of a pixelelectrode forming region is formed, and switching elements (activeelements), other electrodes and lines are formed over the transparentconductive layer by way of an insulation layer. Due to such aconstitution, the feeding resistance with respect to the holdingcapacity can be largely reduced. Further, a trade-off between theenhancement of numerical aperture and the increase of holding capacitycan be eliminated. Representative constitutions of the present inventionare described hereinafter.

(1):

In a liquid crystal display device in which liquid crystal is sandwichedbetween a first substrate and a second substrate which face each otherin an opposed manner, and at least a plurality of gate lines whichextend in the first direction and are arranged parallel to each other, aplurality of drain lines which extend in the second direction whichcrosses the gate lines and are arranged parallel to each other, aplurality of switching elements which are arranged at crossing portionsof the gate lines and the drain lines, and pixel electrodes which aredriven by the switching elements are formed on an inner surface of thefirst substrate,

having an electrode forming layer which include the gate lines, thedrain lines, the switching elements and the pixel electrodes

having a reference electrode layer arranged between the first substrateand the electrode forming layer with first insulation layer between thereference electrode layer and the electrode forming layer, and

holding capacities of the pixels are formed between the pixel electrodesand the reference electrode layer.

Due to such a constitution, the feeding resistance with respect to thestorage capacity is largely reduced so that it is possible to realizethe liquid crystal display device which can realize both of theenhancement of numerical aperture of pixels and the assurance of holdingcapacity.

(2):

In the constitution (1), the electrode forming layer includes the gatelines, a gate insulation layer, the semiconductor layers, the drainlines, a passivation layer and the pixel electrodes in this order overthe first insulation layer, and the holding capacity of the pixel isformed between the pixel electrodes and the reference electrode layer.

Since the holding capacity is constituted of the passivation layer, thegate insulation layer and the first insulation layer which are formedbetween the pixel electrode and the reference electrode layer, thedistance to the reference electrode layer as viewed from the liquidcrystal layer can be largely increased so that the influence of theelectric field of the reference electrode layer on the electric fieldfor driving liquid crystal can be attenuated.

(3):

In the constitution (1), the reference electrode layer is arranged inthe extension direction of the gate lines such that the referenceelectrode layer is arranged parallel to the gate lines and overlapsregions where the pixel electrodes are formed.

Due to such a constitution, the parasitic capacity between the gate lineand the reference electrode layer can be reduced and the potential canbe made stable.

(4):

In the constitution (1), the reference electrode layer is provided to aregion of the first substrate which includes regions in which the gatelines, the drain lines and the pixel electrodes are formed.

Due to such a constitution, the reference electrode layer forms aso-called matted electrode so that the feeding resistance can be furtherreduced and the limitation imposed on the feeding direction can beeliminated.

(5):

In the constitution (1), the passivation layer is formed over the gateinsulation layer, the pixel electrodes are formed over the passivationlayer, and the whole or a portion of the pixel electrodes penetrate thepassivation layer and are brought into contact with the gate insulationlayer.

Due to such a constitution, holding capacity formed between theconductive layers and the pixel electrodes can be adjusted by changingthe area that the pixel electrodes penetrate the passivation layer.

(6):

In the constitution (1), the passivation layer is formed over the gateinsulation layer, the pixel electrodes are formed over the passivationlayer, and the whole or a portion of the pixel electrodes in the pixelregions penetrate the passivation layer and the gate insulation layerand are brought into contact with the first insulation layer.

Due to such a constitution, holding capacity formed between thereference electrode layer and the pixel electrodes can be adjusted bychanging the area that the pixel electrodes penetrate the passivationlayer and the gate insulation layer.

(7):

In the constitution (1), the passivation layer is formed over the gateinsulation layer, the pixel electrodes are formed over the passivationlayer, and the switching elements include source electrodes on the gateinsulation layer which are connected to the pixel electrodes via throughholes formed in the passivation layer and extension portions whichextend along the gate lines or the drain lines at one portions of thesource electrodes.

Due to such a constitution, holding capacity can be adjusted by changingthe length or the width of the extension portions of the sourceelectrodes, that is, by changing the area that the source electrodesoverlap the pixel electrodes.

(8):

In the constitution (1), the first insulation layer is formed of anorganic insulation layer.

Due to such a constitution, the electric distance between the referenceelectrode layer and the electrode forming layer can be increasedcompared to a case in which the insulation layer is provided. Further,parasitic capacity between the reference electrode layer and the gatelines as well as the drain lines can be reduced.

(9):

In the constitution (1), the liquid crystal display device includes alight shielding layer which perform light shielding of gaps definedbetween the vicinities in the extension direction of the drain lines andthe pixel electrodes.

Due to such a constitution, leaking of light can be prevented.

(10):

In the constitution (1), common electrodes which constitute pixelstogether with the pixel electrodes are formed on an inner surface of thesecond substrate.

(11):

In a liquid crystal display device in which liquid crystal is sandwichedbetween a first substrate and a second substrate which face each otherin an opposed manner, and at least a plurality of gate lines whichextend in the first direction and are arranged parallel to each other, aplurality of drain lines which extend in the second direction whichcrosses the gate lines and are arranged parallel to each other, aplurality of switching elements which are arranged at crossing portionsof the gate lines and the drain lines, and pixel electrodes which aredriven by the switching elements are formed on an inner surface of thefirst substrate,

having an electrode forming layer which include the gate lines, thedrain lines, the switching elements and the pixel electrodes,

having a reference electrode layer arranged between the first substrateand the electrode forming layer with first insulation layer between thereference electrode layer and the electrode forming layer, and

the electrode forming layer includes the gate insulation layer, thepassivation layer, a second insulation layer and the pixel electrodes inthis order over the first insulation layer, and

holding capacities of the pixels are formed between the pixel electrodesand the reference electrode layer.

Due to such a constitution, the numerical aperture of the pixels can beenhanced. Since the area of the conductive layers is large, the feedingresistance can be reduced. Further, since the holding capacity is formedby the passivation layer, the gate insulation layer and the firstinsulation layer which are formed between the pixel electrodes and thereference electrode layer, the holding capacity can be easilycontrolled. Further, since the organic insulation layer is also formedover the switching elements, the pixel electrodes and the drain linescan overlap each other so that the numerical aperture is furtherenhanced. When the pixel electrodes and the drain lines overlap eachother, it is possible to eliminate light shielding layers between thevicinities of the extension direction of the drain lines and the pixelelectrodes so that the numerical aperture is further enhanced.

(12):

In the constitution (11), the reference electrode layer is arranged inthe extension direction of the gate lines such that the referenceelectrode layer is arranged parallel to the gate lines and overlapsregions where the pixel electrodes are formed.

Due to such a constitution, the capacity between the gate lines and thereference electrode layers can be reduced so that the increase ofholding capacity can be suppressed and the potential can be made stable.

(13):

In the constitution (11), the reference electrode layer is provided to aregion of the first substrate which includes regions in which the gatelines, the drain lines and the pixel electrodes are formed.

Due to such a constitution, the reference electrode layer forms aso-called matted electrode so that the feeding resistance can be furtherreduced and the limitation imposed on the feeding direction can beeliminated.

(14):

In the constitution (11), the first organic insulation layer is formedof color filters.

Due to such a constitution, the numerical aperture of the pixels isenhanced. Since the area of the conductive layers is large, the feedingresistance can be reduced. Further, since the holding capacity is formedby the passivation layer, the gate insulation layer and the color filterlayer which is made of organic material and exhibits small dielectricconstant between the pixel electrodes and the reference electrode layer,the increase of parasitic capacity between lines can be suppressed.Still further, since the color filter layer is formed over the firstsubstrate, the tolerance of alignment of the first substrate with thesecond substrate is increased.

(15):

In the constitution (14), the reference electrode layer is arranged inthe extension direction of the gate lines such that the referenceelectrode layer is arranged parallel to the gate lines and overlapsregions where the pixel electrodes are formed.

Due to such a constitution, the capacity between the gate lines and theconductive layer can be reduced and the potential can be made stable.

(16):

In the constitution (14), the reference electrode layer is provided to aregion of the first substrate which includes regions in which the gatelines, the drain lines and the pixel electrodes are formed.

Due to such a constitution, the reference electrode layer forms aso-called matted electrode so that the feeding resistance can be furtherreduced and the limitation imposed on the feeding direction can beeliminated.

(17):

In the constitution (11), the first insulation layer is an organicinsulation layer.

Due to such a constitution, the electric distance between the referenceelectrode layer and the electrode forming layer can be increasedcompared to a case in which the insulation layer is provided. Further,the parasitic capacity between the reference electrode layer and thegate line as well as the drain line can be reduced.

(18):

In the constitution (11), the liquid crystal display device includes alight shielding layer which performs light shielding of gaps definedbetween the vicinities in the extension direction of the drain lines andthe pixel electrodes.

Due to such a constitution, leaking of light can be prevented.

(19):

In the constitution (11), common electrodes which constitute pixelstogether with the pixel electrodes are formed on an inner surface of thesecond substrate.

(20):

In a liquid crystal display device in which liquid crystal is sandwichedbetween a first substrate and a second substrate which face each otherin an opposed manner, and at least a plurality of gate lines whichextend in the first direction and are arranged parallel to each other, aplurality of drain lines which extend in the second direction whichcrosses the gate lines and are arranged parallel to each other, aplurality of switching elements which are arranged at crossing portionsof the gate lines and the drain lines, and pixel electrodes which aredriven by the switching elements are formed on an inner surface of thefirst substrate, and pixel regions are formed of a plurality of pixelelectrodes,

having an electrode forming layer which include the gate lines, thedrain lines, the switching elements and the pixel electrodes

having a reference electrode layer arranged between the first substrateand the electrode forming layer with first insulation layer between thereference electrode layer and the electrode forming layer, and

the electrode forming layer includes the gate insulation layer, thepassivation layer and the pixel electrode in this order over the firstinsulation layer and further includes a capacitive electrode layer whichis formed over the first insulation layer and is connected to the pixelelectrodes, and

holding capacities of the pixels are formed among the pixel electrodes,the reference electrode layer and the capacitive electrode layer.

Due to such a constitution, the numerical aperture of the pixels can beenhanced. Since the area of the conductive layers is large, the feedingresistance can be reduced. Further, since the holding capacity can beadjusted by changing the area and size of the capacitive electrodelayer, it is possible to realize both of the enhancement of numericalaperture and the assurance of holding capacity. Still further, when theorganic insulation layer is formed between the passivation layer and thepixel electrodes, it is possible to make the pixel electrodes and thedrain lines overlap each other and hence, the numerical aperture isfurther enhanced. When the pixel electrodes and the drain lines overlapeach other, it is possible to eliminate light shielding layers betweenthe vicinities of the extension direction of the drain lines and thepixel electrodes so that the numerical aperture is further enhanced.

(21):

In the constitution (20), the reference electrode layer is arranged inthe extension direction of the gate lines such that the referenceelectrode layer is arranged parallel to the gate lines and overlapsregions where the pixel electrodes are formed.

Due to such a constitution, the capacity between the gate lines and thereference electrode layer can be reduced and the potential can be madestable.

(22):

In the constitution (20), the reference electrode layer is provided to aregion of the first substrate which includes regions in which the gatelines, the drain lines and the pixel electrodes are formed.

Due to such a constitution, the reference electrode layer forms aso-called matted electrode so that the feeding resistance can be furtherreduced and the limitation imposed on the feeding direction can beeliminated.

(23):

In the constitution (20), the switching elements include sourceelectrodes over the gate insulation layer which are connected to thepixel electrodes via through holes formed in the passivation layer, andthe capacitive electrode layer is connected to the source electrodes andis provided to regions of the pixel electrodes.

Due to such a constitution, the holding capacity can be adjusted bychanging the size of the capacitive electrode layer.

(24):

In the constitution (20), the first insulation layer is formed of colorfilters.

Due to such a constitution, the numerical aperture of the pixels can beenhanced. Since the area of the conductive layers is large, the feedingresistance can be reduced. Further, since the color filter layer isformed over the first substrate, the tolerance of alignment of the firstsubstrate with the second substrate can be increased.

(25):

In the constitution (20), the capacitive electrode layer is formed overthe passivation layer, the organic insulation layer is formed over thepassivation layer, the pixel electrodes are formed over the organicinsulation layer and are connected to the capacitive electrode layer viathrough holes formed in the organic insulation layer.

Due to such a constitution, the holding capacity can be adjusted bychanging the size of the capacitive electrode layer.

(26):

In the constitution (20), the capacitive electrode layer is formed overthe gate insulation layer, and the pixel electrodes are connected to thecapacitive electrode layer via through holes formed in the passivationlayer.

Due to such a constitution, the holding capacity can be adjusted bychanging the size of the capacitive electrode layer.

(27):

In the constitution (20), the capacitive electrode layer is formed overthe first insulation layer, and the pixel electrodes penetrate thepassivation layer and are connected to the capacitive electrode layervia through holes formed in the gate insulation layer.

Due to such a constitution, the holding capacity formed between theconductive layer and the pixel electrodes can be adjusted by changingthe area that the pixel electrodes penetrate the passivation layer andthe gate insulation layer.

(28):

In the constitution (20), the first insulation layer is formed of anorganic insulation layer.

Due to such a constitution, the electric distance between the referenceelectrode layer and the electrode forming layer can be increasedcompared to a case in which the insulation layer is provided. Further,parasitic capacity between the reference electrode layer and the gatelines as well as the drain lines can be reduced.

(29):

In the constitution (20), the liquid crystal display device includes alight shielding layer which performs light shielding of gaps definedbetween the vicinities in the extension direction of the drain lines andthe pixel electrodes.

Due to such a constitution, leaking of light can be prevented.

(30):

In the constitution (20), common electrodes which constitute pixelstogether with the pixel electrodes are formed on an inner surface of thesecond substrate.

(31):

In a liquid crystal display device in which liquid crystal is sandwichedbetween a first substrate and a second substrate which face each otherin an opposed manner, and at least a plurality of gate lines whichextend in the first direction and are arranged parallel to each other, aplurality of drain lines which extend in the second direction whichcrosses the gate lines and are arranged parallel to each other, aplurality of switching elements which are arranged at crossing portionsof the gate lines and the drain lines, and pixel electrodes which aredriven by the switching elements are formed on an inner surface of thefirst substrate, and pixel regions are formed of a plurality of pixelelectrodes,

the improvement is characterized in that between an electrode forminglayer which is constituted of the gate lines, the drain lines, theswitching elements and the pixel electrodes including the pixel regionsof the first substrate and the first substrate side, a referenceelectrode layer which is insulated by a first insulation layer withrespect to the electrode forming layer is formed,

wherein having an electrode forming layer which include the gate lines,the drain lines, the switching elements and the pixel electrodes,

having a reference electrode layer arranged between the first substrateand the electrode forming layer with first insulation layer between thereference electrode layer and the electrode forming layer, and

the electrode forming layer includes the gate insulation layer, thepassivation layer and the pixel electrode in this order over the firstinsulation layer and further includes a capacitive electrode layer whichis connected to the pixel electrodes between the first insulation layerand the passivation layer, and

holding capacities of the pixels are formed among the pixel electrodes,the reference electrode layer and the capacitive electrode layer.

Due to such a constitution, the numerical aperture of pixels can beenhanced. Further, since the area of the reference electrode layer islarge, the feeding resistance can be reduced. Still further, the holdingcapacity can be adjusted by changing the area and the shape of thecapacitive electrode layer.

(32):

In the constitution (31), the reference electrode layer is arranged inthe extension direction of the gate lines such that the referenceelectrode layer is arranged parallel to the gate lines and overlapsregions where the pixel electrodes are formed.

Due to such a constitution, the capacity between the gate lines and thereference electrode layer can be reduced. The increase of parasiticcapacity between lines can be suppressed. Further, the potential can bemade stable.

(33):

In the constitution (31), the reference electrode layer is provided to aregion of the first substrate which includes regions in which the gatelines, the drain lines and the pixel electrodes are formed.

Due to such a constitution, the reference electrode layer forms aso-called matted electrode so that the feeding resistance can be furtherreduced and the limitation imposed on the feeding direction can beeliminated.

(34):

In the constitution (31), the organic insulation layer is formed ofcolor filters.

Due to such a constitution, the numerical aperture of the pixels isenhanced. Since the area of the reference electrode layers is large, thefeeding resistance can be reduced. Further, since the color filters areformed of organic films, the parasitic capacitance between lines can bereduced. Still further, since the color filter layer is formed over thefirst substrate, the tolerance of alignment of the first substrate withthe second substrate is increased.

(35):

In the constitution (31), the first insulation layer is formed of anorganic insulation layer.

Due to such a constitution, the electric distance between the referenceelectrode layer and the electrode forming layer can be increasedcompared to a case in which the insulation layer is provided. Further,the parasitic capacity between the reference electrode layer and thegate lines as well as the drain lines can be reduced.

(36):

In the constitution (31), the liquid crystal display device includes alight shielding layer which performs light shielding of gaps definedbetween the vicinities in the extension direction of the drain lines andthe pixel electrodes.

Due to such a constitution, leaking of light can be prevented.

(37):

In the constitution (31), the capacitive electrode layer is formed overthe first insulation layer, and the capacitive electrode layer isconnected to the reference electrode layer via through holes whichpenetrate the first insulation layer.

Due to such a constitution, the holding capacity formed between thereference electrode layer and the pixel electrodes can be adjusted bychanging the area of the capacitive electrode layer connected to thereference electrode layer.

(38):

In the constitution (31), the capacitive electrode layer is formed overthe gate insulation layer, and the capacitive electrode layer isconnected to the reference electrode layer via through holes whichpenetrate the gate insulation layer.

Due to such a constitution, the holding capacity formed between thereference electrode layer and the pixel electrodes can be adjusted bychanging the area of the capacitive electrode layer connected to thereference electrode layer.

(39):

In the constitution (31), the capacitive electrode layer is formed overthe passivation layer, and the capacitive electrode layer is connectedto the reference electrode layer via through holes which penetrate thepassivation layer, the gate insulation layer and the first insulationlayer.

Due to such a constitution, the holding capacity formed between thereference electrode layer and the pixel electrodes can be adjusted bychanging the area of the capacitive electrode layer connected to thereference electrode layer.

(40):

In the constitution (31), the capacitive electrode layer is formed overthe gate insulation layer, a second capacitive electrode layer is formedover the first insulation layer, the pixel electrode is connected to thecapacitive electrode layer via through holes formed in the passivationlayer, and the second capacitive electrode layer is connected to thereference electrode layer via through holes formed in the firstinsulation layer.

Due to such a constitution, the holding capacity can be easily adjustedby changing the areas of the capacitive electrode layer and the secondcapacitive electrode layer. Further, the holding capacity can be furtherincreased.

(41):

In the constitution (31), the first insulation layer is formed of anorganic insulation layer.

Due to such a constitution, the electric distance between the referenceelectrode layer and the electrode forming layer can be increasedcompared to a case that the insulation layer is provided. Further, theparasitic capacity among the reference electrode layer, the gate linesand the drain lines can be reduced.

(42):

In the constitution (31), the liquid crystal display device includes alight shielding layer which performs light shielding of gaps definedbetween the vicinities in the extension direction of the drain lines andthe pixel electrodes.

Due to such a constitution, leaking of light can be prevented.

(43):

In the constitution (31), common electrodes which constitute pixelstogether with the pixel electrodes are formed on an inner surface of thesecond substrate.

(44):

In a liquid crystal display device in which liquid crystal is sandwichedbetween a first substrate and a second substrate which face each otherin an opposed manner, and at least a plurality of gate lines whichextend in the first direction and are arranged parallel to each other, aplurality of drain lines which extend in the second direction whichcrosses the gate lines and are arranged parallel to each other, aplurality of switching elements which are arranged at crossing portionsof the gate lines and the drain lines, pixel electrodes which are drivenby the switching elements, and counter electrodes which generate anelectric field for driving pixels between the pixel electrodes and thecounter electrodes are formed on an inner surface of the firstsubstrate,

having an electrode forming layer which include the gate lines, thedrain lines, the switching elements and the pixel electrodes

having a reference electrode layer arranged between the first substrateand the electrode forming layer with first insulation layer between thereference electrode layer and the electrode forming layer, and

holding capacities of the pixels are formed among the pixel electrodesand the reference electrode layer.

Due to such a constitution, the liquid crystal display device canachieve both of the large numerical aperture and the large holdingcapacity. Further, since it is unnecessary to increase the areas of thepixel electrodes and the lines for forming the holding capacity, thenumerical aperture is enhanced. Still further, since the area of thereference electrode layer is large, the feeding resistance can bereduced.

(45):

In the constitution (44), the counter electrodes are formed over theorganic insulation layer, and the counter electrodes are connected tothe reference electrode layer via through holes formed in the firstinsulation layer.

Due to such a constitution, the area of the reference electrode layercan be increased and hence, the feeding resistance to the counterelectrodes can be reduced.

(46):

In the constitution (44), the counter electrodes are formed over thegate insulation layer, and the counter electrodes are connected to thereference electrode layer via through holes formed in the gateinsulation layer and the first insulation layer.

Due to such a constitution, the area of the reference electrode layercan be increased and hence, the feeding resistance can be reduced.

(47):

In the constitution (44), the counter electrodes are formed over thepassivation layer, and the counter electrodes are connected to thereference electrode layer via through holes formed in the passivationlayer, the gate insulation layer and the first insulation layer.

Due to such a constitution, the area of the reference electrode layercan be increased and hence, the feeding resistance can be reduced.

(48):

In the constitution (44), the reference electrode layer is arranged inthe extension direction of the gate lines such that the referenceelectrode layer is arranged parallel to the gate lines and overlapsregions where the pixel electrodes are formed.

Due to such a constitution, the parasitic capacity formed between thegate lines and the reference electrode layer can be reduced and thepotential can be made stable.

(49):

In the constitution (44), the reference electrode layer is provided to aregion of the first substrate which includes regions in which the gatelines, the drain lines and the pixel electrodes are formed.

Due to such a constitution, the reference electrode layer forms aso-called matted electrode so that the feeding resistance can be furtherreduced and the limitation imposed on the feeding direction can beeliminated.

(50):

In the constitution (44), the counter electrodes are formed over thefirst insulation layer, the counter electrodes extend to the neighboringpixel regions by crossing the drain lines and are connected to thereference electrode layers of the neighboring pixel regions via throughholes formed in the first insulation layer.

Due to such a constitution, even when the through holes are formedinsufficiently, the feeding of electricity is performed through thecounter electrodes from the neighboring pixel sides. Further, when thethrough holes which connect each counter electrode and each referenceelectrode are formed in a plural number for every pixel, the reliabilityof connection between the electrode layers can be enhanced.

(51):

In the constitution (44), the counter electrodes are formed over anorganic insulation layer, conductive layers which extend to theneighboring pixel regions by crossing the drain lines are formed overthe gate insulation layer, the counter electrodes are connected to theconductive layers via through holes formed in the gate insulation layer,and the conductive layers are connected to the reference electrode layervia through holes formed in the first insulation layer.

Due to such a constitution, even when the through holes are formedinsufficiently, the feeding of electricity is performed through theconductive layers from the neighboring pixel sides. Further, when thethrough holes which connect each counter electrode and each referenceelectrode are formed in a plural number for every pixel, the reliabilityof connection between the electrode layers can be enhanced.

(52):

In the constitution (44), the counter electrodes are formed over apassivation layer, conductive layers which extend to the neighboringpixel regions by crossing the drain lines are formed over the gateinsulation layer, the counter electrodes are connected to the conductivelayers via through holes formed in the passivation layer and the gateinsulation layer, and the conductive layers are connected to thereference electrode layer via through holes formed in the firstinsulation layer.

Due to such a constitution, even when the through holes are formedinsufficiently, the feeding of electricity is performed through theconductive layers from the neighboring pixel sides. Further, when thethrough holes which connect each counter electrode and each referenceelectrode are formed in a plural number for every pixel, the reliabilityof connection between the electrode layers can be enhanced.

(53):

In the constitution (44), a color filter layer is formed between thereference electrode which is formed below the first insulation layer andthe first substrate.

Due to such a constitution, it is possible to isolate the color filterlayer from the liquid crystal layer with the use of the referenceelectrodes and hence, it is possible to prevent the liquid crystal frombeing contaminated by constituent materials of the color filter layer.

(54):

In the constitution (44), the counter electrodes are formed over thefirst insulation layer parallel to the extension direction of the gatelines, the counter electrodes extends over the pixel region, and thecounter electrodes are connected to the reference electrodes inrespective pixel regions via through holes formed in the firstinsulation layer.

Due to such a constitution, holding capacity is formed at portions wherethe counter electrodes and the pixel electrodes overlap each other, andthe gate insulation layer functions as a dielectric of the holdingcapacity and hence, the constitution is suitable for increasing theholding capacity.

(55):

In the constitution (44), the counter electrodes are connected to thereference electrodes in respective pixel regions via through holesformed in the first insulation layer and the gate insulation layer in apenetrating manner, and holding capacities are formed at overlappingportions of the counter electrodes and the pixel electrodes.

(56):

In the constitution (44), the pixel electrodes are formed over the gateinsulation layer, the counter electrodes are formed below the gateinsulation layers, the counter electrodes are connected to the referenceelectrodes via through holes formed in the first insulation layer, andholding capacities are formed by the counter electrodes and the pixelelectrodes.

(57):

In the constitution (44), the pixel electrodes and the counterelectrodes are formed on the same layer.

(58):

In the constitution (44), the counter electrodes are formed over thepixel electrodes and are connected to the reference electrodes by way ofthrough holes formed in a gate insulation film and a first insulationfilm.

(59):

In the constitution (44), the first insulation layer is formed of anorganic insulation layer.

(60):

In a liquid crystal display device in which liquid crystal is sandwichedbetween a first substrate and a second substrate which face each otherin an opposed manner, and at least a plurality of gate lines whichextend in the first direction and are arranged parallel to each other, aplurality of drain lines which extend in the second direction whichcrosses the gate lines and are arranged parallel to each other, aplurality of switching elements which are arranged at crossing portionsof the gate lines and the drain lines, and pixel electrodes which aredriven by the switching elements are formed on an inner surface of thefirst substrate,

having an electrode forming layer which include the gate lines, thedrain lines, the switching elements and the pixel electrodes,

having a counter electrode layer arranged between the first substrateand the electrode forming layer with first insulation layer between thereference electrode layer and the electrode forming layer, and thereference electrode layer overlapped substantially all region of thepixel electrode and function as a counter electrode, and

holding capacities of the pixels are formed between the pixel electrodesand the counter electrode layer.

Due to such a constitution, the feeding resistance with respect to theholding capacity can be largely reduced so that the image quality isenhanced. Further, it is possible to realize both of the enhancement ofnumerical aperture and the assurance of holding capacity.

(61):

In the constitution (60), the counter electrode layer is arranged in theextension direction of the gate lines such that the counter electrodelayer is arranged parallel to the gate lines and overlaps regions wherethe pixel electrodes are formed.

Due to such a constitution, an independent reference electrode layer isunnecessary, the parasitic capacity between the gate lines and theconductive layers can be reduced, and the potential can be made stable.

(62):

In the constitution (60), the counter electrode layer is provided to aregion of the first substrate which includes regions in which the gatelines, the drain lines and the pixel electrodes are formed.

Due to such a constitution, the counter electrode layer forms aso-called matted electrode so that the feeding resistance can be furtherreduced and the limitation imposed on the feeding direction can beeliminated.

(63):

In the constitution (60), the whole or a portion of the layerconstitution of insulation layers below the pixel electrodes and thewhole or a portion of the region are removed.

Due to such a constitution, the strength of electric field generatedbetween the pixel electrodes and the counter electrodes is increased sothat the driving voltage can be reduced.

(64):

In the constitution (60), over the counter electrode layer, connectionlines which are arranged parallel to the extension direction of the gatelines and are connected to counter electrodes which are disposed closeto the counter electrode are formed.

(65):

In the constitution (60), below the counter electrode layer, connectionlines which are arranged parallel to the extension direction of the gatelines and are connected to counter electrodes which are disposed closeto the counter electrode are formed.

Due to the above-mentioned constitution (64) or (65), even when thethrough holes are formed insufficiently, the feeding of electricity isperformed through the connection lines from the neighboring pixel sides.Further, when the through holes which connect each counter electrodewith each reference electrode are formed in a plural number for everypixel, the reliability of connection of the electrode layers can beenhanced.

(66):

In the constitution (60), the first insulation layer is removed atportions of the pixel regions.

Due to such a constitution, a plurality of regions which differ indriving voltage can be formed in the pixel region so that themulti-domain effect can be obtained.

(67):

In the constitution (60), a color filter layer is formed between thereference electrodes which are arranged below the first insulation layerand the first substrate.

(68):

In the constitution (60), the first insulation layer is formed of anorganic insulation layer.

(69):

In the constitution (68), the organic insulation layer is formed ofcolor filters.

(70):

In a liquid crystal display device, liquid crystal sandwiched between afirst substrate and a second substrate which face each other in anopposed manner;

a plurality of gate lines which extend in the first direction and arearranged parallel to each other;

a plurality of drain lines which extend in the second direction whichcrosses the gate lines and are arranged parallel to each other;

a plurality of switching elements which are arranged at crossingportions of the gate lines and the drain lines;

pixel electrodes which are driven by the switching elements are formedon an inner surface of the first substrate,

counter electrodes which generate an electric field for driving pixelsbetween the pixel electrodes formed on an inner surface of the first;

having an electrode forming layer which include the gate lines, thedrain lines, the switching elements and the pixel electrodes,

having a reference electrode layer arranged between the first substrateand the electrode forming layer with first insulation layer between thereference electrode layer and the electrode forming layer,

the electrode forming layer is formed by laminating the gate insulationlayer, the passivation layer, an organic insulation layer and counterelectrodes in this order over the first insulation layer,

the counter electrode layer is shared by a pixel region which isarranged close to the pixel region in the extension direction of thegate lines and a pixel region which is arranged close to the pixelregion in the extension direction of the drain lines,

the counter electrode layer is connected to the reference electrodelayer via through holes which electrically penetrate the organicinsulation layer, the passivation layer, the gate insulation layer andthe first insulation layer, and

holding capacities of the pixels are formed between the pixel electrodesand the reference electrode layer.

(71):

In the constitution (70), the liquid crystal display device includes acapacitive electrode layer which is disposed below the pixel electrodesand is formed between the first insulation layer and the gate insulationlayer, and the capacitive electrode layer is connected to the referenceelectrode layer via through holes.

Due to such a constitution, the holding capacity can be increased andadjusted by the capacitive electrode layer.

(72):

In the constitution (70), removing regions are formed in the firstinsulation layer disposed below the pixel electrodes.

Due to such a constitution, the holding capacity formed between thepixel electrode and the reference electrode layer can be increased.

(73):

In the constitution (70), the first insulation layer is formed of anorganic insulation layer.

(74):

In the constitution (73), the organic insulation layer is formed ofcolor filters.

(75):

In an image display device in which at least a plurality of gate lineswhich extend in the first direction and are arranged parallel to eachother, a plurality of drain lines which extend in the second directionwhich crosses the gate lines and are arranged parallel to each other, aplurality of switching elements which are arranged at crossing portionsof the gate lines and the drain lines, and pixel electrodes which aredriven by the switching elements are formed on an inner surface of thefirst substrate,

having an electrode forming layer which include the gate lines, thedrain lines, the switching elements and the pixel electrodes,

having a reference electrode layer arranged between the first substrateand the electrode forming layer with first insulation layer between thereference electrode layer and the electrode forming layer, and

the reference electrode layer is substantially formed over the wholesurface of the pixel regions and shared by a plurality of pixels.

(76):

In the constitution (75), a semiconductor layer which constitutes theswitching element has crystalline property.

(77):

An image display device being characterized in that a referenceelectrode layer formed between a substrate and a semiconductor havingcrystalline property, and having insulation layer between the referenceelectrode layer and the semiconductor, and the reference electrode layeris formed over substantially the whole surface of a pixel region and isshared by a plurality of pixels.

(78):

In the constitution (77), the reference electrode layer is formed of atransparent electrode.

(79):

A manufacturing method of an image display device comprises at least afirst step in which a reference electrode layer which is shared by aplurality of pixels is formed on a substantially whole surface of apixel region on a substrate, a second step in which an insulation layeris formed, and a third step in which a semiconductor layer is formed inthis order, and thereafter, further comprise a fourth step in whichlaser beams are irradiated to the semiconductor layer.

(80):

A manufacturing method of an image display device comprises at least afirst step in which a reference electrode layer which is shared by aplurality of pixels is formed on a substantially whole surface of apixel region on a substrate, a second step in which an insulation layeris formed, and a third step in which a semiconductor layer is formed inthis order, and thereafter, further comprises a fourth step in whichions are implanted into the semiconductor layer.

The present invention is not limited to the above-mentioned respectiveconstitutions and the constitutions of embodiments which will beexplained later and various modifications are considered withoutdeparting from the technical concept of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of the vicinity of one pixel of a liquid crystaldisplay device for schematically explaining the pixel constitution ofone embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along a line I-I in FIG. 1.

FIG. 3 is a cross-sectional view taken along a line II-II in FIG. 1.

FIG. 4 is a plan view of the vicinity of one pixel of a liquid crystaldisplay device for schematically explaining the pixel constitution ofanother embodiment of the present invention.

FIG. 5 is a cross-sectional view taken along a line I-I in FIG. 4.

FIG. 6 is a cross-sectional view taken along a line II-II in FIG. 4.

FIG. 7 is a plan view of the vicinity of one pixel of a liquid crystaldisplay device for schematically explaining the pixel constitution ofstill another embodiment of the present invention.

FIG. 8 is a cross-sectional view taken along a line I-I in FIG. 7.

FIG. 9 is a cross-sectional view taken along a line I-I in FIG. 8showing the vicinity of one pixel of a liquid crystal display device forschematically explaining the pixel constitution of still anotherembodiment of the present invention.

FIG. 10 is a plan view of the vicinity of one pixel of a liquid crystaldisplay device for schematically explaining the pixel constitution ofstill another embodiment of the present invention.

FIG. 11 is a plan view of the vicinity of one pixel of a liquid crystaldisplay device for schematically explaining the pixel constitution ofstill another embodiment of the present invention.

FIG. 12 is a plan view of the vicinity of one pixel of a liquid crystaldisplay device for schematically explaining the pixel constitution ofstill another embodiment of the present invention.

FIG. 13 is a cross-sectional view taken along a line I-I in FIG. 12.

FIG. 14 is a cross-sectional view taken along a line II-II in FIG. 12.

FIG. 15 is a plan view of the vicinity of one pixel of a liquid crystaldisplay device for schematically explaining the pixel constitution ofstill another embodiment of the present invention.

FIG. 16 is a cross-sectional view taken along a line I-I in FIG. 15.

FIG. 17 is across-sectional view taken along a line II-II in FIG. 15.

FIG. 18 is a cross-sectional view taken along a line I-I in FIG. 15 of aliquid crystal display device for schematically explaining the pixelconstitution of another embodiment of the present invention.

FIG. 19 is a cross-sectional view taken along a line II-II in FIG. 18.

FIG. 20 is a plan view of the vicinity of one pixel of a liquid crystaldisplay device for schematically explaining the pixel constitution ofstill another embodiment of the present invention.

FIG. 21 is a cross-sectional view taken along a line III-III in FIG. 20.

FIG. 22 is a cross-sectional view taken along the line III-III in FIG.20 for schematically explaining the pixel constitution of anotherembodiment of the present invention.

FIG. 23 is a cross-sectional view taken along the line III-III in FIG.20 for schematically explaining the pixel constitution of anotherembodiment of the present invention.

FIG. 24 is a plan view of the vicinity of one pixel of a liquid crystaldisplay device for schematically explaining the pixel constitution ofstill another embodiment of the present invention.

FIG. 25 is a cross-sectional view taken along a line III-III in FIG. 24.

FIG. 26 is a cross-sectional view taken along a line III-III in FIG. 24of the vicinity of one pixel of the liquid crystal display device forschematically explaining the pixel constitution of still anotherembodiment of the present invention.

FIG. 27 is a cross-sectional view taken along a line III-III in FIG. 24of the vicinity of one pixel of the liquid crystal display device forschematically explaining the pixel constitution of still anotherembodiment of the present invention.

FIG. 28 is a plan view of the vicinity of one pixel of a liquid crystaldisplay device for schematically explaining the pixel constitution ofstill another embodiment of the present invention.

FIG. 29 is a cross-sectional view taken along a line III-III in FIG. 28.

FIG. 30 is a cross-sectional view taken along a line III-III in FIG. 28of the vicinity of one pixel of the liquid crystal display device forschematically explaining the pixel constitution of still anotherembodiment of the present invention.

FIG. 31 is a plan view of the vicinity of one pixel of a liquid crystaldisplay device for schematically explaining the pixel constitution ofstill another embodiment of the present invention.

FIG. 32 is a cross-sectional view taken along a line III-III in FIG. 31.

FIG. 33 is a cross-sectional view taken along a line III-III in FIG. 31of the vicinity of one pixel of the liquid crystal display device forschematically explaining the pixel constitution of still anotherembodiment of the present invention.

FIG. 34 is a plan view of the vicinity of one pixel of a liquid crystaldisplay device for schematically explaining the pixel constitution ofstill another embodiment of the present invention.

FIG. 35 is a cross-sectional view taken along a line III-III in FIG. 34.

FIG. 36 is a cross-sectional view taken along a line III-III in FIG. 34of the vicinity of one pixel of the liquid crystal display device forschematically explaining the pixel constitution of still anotherembodiment of the present invention.

FIG. 37 is a cross-sectional view taken along a line III-III in FIG. 34of the vicinity of one pixel of the liquid crystal display device forschematically explaining the pixel constitution of still anotherembodiment of the present invention.

FIG. 38 is a plan view of the vicinity of one pixel of a liquid crystaldisplay device for schematically explaining the pixel constitution ofstill another embodiment of the present invention.

FIG. 39 is a cross-sectional view taken along a line III-III in FIG. 38.

FIG. 40 is a cross-sectional view taken along a line III-III in FIG. 38of the vicinity of one pixel of the liquid crystal display device forschematically explaining the pixel constitution of still anotherembodiment of the present invention.

FIG. 41 is a cross-sectional view taken along a line III-III in FIG. 38of the vicinity of one pixel of the liquid crystal display device forschematically explaining the pixel constitution of still anotherembodiment of the present invention.

FIG. 42 is a plan view of the vicinity of one pixel of a liquid crystaldisplay device for schematically explaining the pixel constitution ofstill another embodiment of the present invention.

FIG. 43 is a cross-sectional view taken along a line III-III in FIG. 38.

FIG. 44 is a cross-sectional view taken along a line III-III in FIG. 42of the vicinity of one pixel of the liquid crystal display device forschematically explaining the pixel constitution of still anotherembodiment of the present invention.

FIG. 45 is a plan view of a through hole and a metal light shieldingfilm in still another embodiment of the present invention.

FIG. 46 is a cross-sectional view of an essential part for explainingstill another embodiment of the present invention.

FIG. 47 is a plan view of the vicinity of one pixel of a liquid crystaldisplay device for schematically explaining the pixel constitution ofstill another embodiment of the present invention.

FIG. 48 is a cross-sectional view taken along a line III-III in FIG. 47.

FIG. 49 is a cross-sectional view taken along a line IV-IV in FIG. 47 ofthe vicinity of one pixel of the liquid crystal display device forschematically explaining the pixel constitution of still anotherembodiment of the present invention.

FIG. 50 is a cross-sectional view taken along a line IV-IV in FIG. 47 ofthe vicinity of one pixel of the liquid crystal display device forschematically explaining the pixel constitution of still anotherembodiment of the present invention.

FIG. 51 is a plan view of the vicinity of one pixel of a liquid crystaldisplay device for schematically explaining the pixel constitution ofstill another embodiment of the present invention.

FIG. 52 is a cross-sectional view taken along a line V-V in FIG. 51.

FIG. 53 is a cross-sectional view taken along a line V-V in FIG. 51showing the vicinity of one pixel of a liquid crystal display device forschematically explaining the pixel constitution of still anotherembodiment of the present invention.

FIG. 54 is a cross-sectional view taken along a line V-V in FIG. 51showing the vicinity of one pixel of a liquid crystal display device forschematically explaining the pixel constitution of still anotherembodiment of the present invention.

FIG. 55 is a cross-sectional view taken along a line V-V in FIG. 51showing the vicinity of one pixel of a liquid crystal display device forschematically explaining the pixel constitution of still anotherembodiment of the present invention.

FIG. 56 is a plan view of the vicinity of one pixel of a liquid crystaldisplay device for explaining a modification of the embodiments shown inFIG. 47 to FIG. 55.

FIG. 57 is a plan view of the vicinity of one pixel of a liquid crystaldisplay device for schematically explaining the pixel constitution ofstill another embodiment of the present invention.

FIG. 58 is a cross-sectional view taken along a line VI-VI in FIG. 57.

FIG. 59 is a cross-sectional view taken along a line VI-VI in FIG. 57showing the vicinity of one pixel of a liquid crystal display device forschematically explaining the pixel constitution of still anotherembodiment of the present invention.

FIG. 60 is a plan view of the vicinity of one pixel of a liquid crystaldisplay device for schematically explaining the pixel constitution ofstill another embodiment of the present invention.

FIG. 61 is a cross-sectional view taken along a line VII-VII in FIG. 60.

FIG. 62 is a cross-sectional view taken along a line VIII-VIII in FIG.60.

FIG. 63 is a cross-sectional view taken along a line VII-VII in FIG. 60showing the vicinity of one pixel of a liquid crystal display device forschematically explaining the pixel constitution of still anotherembodiment of the present invention.

FIG. 64 is a plan view of a portion of a thin film transistor TFT of aliquid crystal display device for schematically explaining an essentialpart of the pixel constitution of still another embodiment of thepresent invention.

FIG. 65 is a plan view of the vicinity of one pixel of a liquid crystaldisplay device for schematically explaining an essential part of thepixel constitution of still another embodiment of the present invention.

FIG. 66 is a cross sectional view taken along a line IX-IX in FIG. 65.

FIG. 67 is a cross-sectional view taken along a line IX-IX in FIG. 65showing the vicinity of one pixel of a liquid crystal display device forschematically explaining an essential part of the pixel constitution ofstill another embodiment of the present invention.

FIG. 68 is a plan view of the vicinity of one pixel of a liquid crystaldisplay device for schematically explaining an essential part of thepixel constitution of still another embodiment of the present invention.

FIG. 69 is a cross sectional view taken along a line X-X in FIG. 68.

FIG. 70 is a cross-sectional view taken along a line X-X in FIG. 68showing the vicinity of one pixel of a liquid crystal display device forschematically explaining an essential part of the pixel constitution ofstill another embodiment of the present invention.

FIG. 71 is a plan view of the vicinity of one pixel of a liquid crystaldisplay device for schematically explaining an essential part of thepixel constitution of still another embodiment of the present invention.

FIG. 72 is a cross sectional view taken along a line XI-XI in FIG. 71.

FIG. 73 is a cross-sectional view taken along a line XI-XI in FIG. 68showing the vicinity of one pixel of a liquid crystal display device forschematically explaining an essential part of the pixel constitution ofstill another embodiment of the present invention.

FIG. 74 is a plan view of the vicinity of one pixel of a liquid crystaldisplay device for schematically explaining an essential part of thepixel constitution of still another embodiment of the present invention.

FIG. 75 is a cross sectional view taken along a line XII-XII in FIG. 74.

FIG. 76 is a cross-sectional view taken along a line XII-XII in FIG. 74showing the vicinity of one pixel of a liquid crystal display device forschematically explaining an essential part of the pixel constitution ofstill another embodiment of the present invention.

FIG. 77 is a cross-sectional view taken along a line XII-XII in FIG. 74showing the vicinity of one pixel of a liquid crystal display device forschematically explaining an essential part of the pixel constitution ofstill another embodiment of the present invention.

FIG. 78 is a cross-sectional view taken along a line XII-XII in FIG. 74showing the vicinity of one pixel of a liquid crystal display device forschematically explaining an essential part of the pixel constitution ofstill another embodiment of the present invention.

FIG. 79 is a cross-sectional view taken along a line XII-XII in FIG. 74showing the vicinity of one pixel of a liquid crystal display device forschematically explaining an essential part of the pixel constitution ofstill another embodiment of the present invention.

FIG. 80 is an explanatory view for explaining the constitution of asubstrate of the liquid crystal display device of the present invention.

FIG. 81 is an explanatory view showing a state in which a tape carrierpackage on which a driving circuit is formed is mounted on the firstsubstrate at a terminal region.

FIG. 82 is an explanatory view showing a state in which a drivingcircuit chip is directly mounted on the first substrate at the terminalregion.

FIG. 83 is an explanatory view of an example of layout of a liquidcrystal filling port for allowing liquid crystal to be filled and sealedbetween two substrates.

FIG. 84 is a schematic cross-sectional view of the liquid crystaldisplay device of the present invention.

FIG. 85 is a plan view for schematically explaining a terminal region ofa gate driving circuit mounted in a tape carrier package method FIG. 86is a plan view for schematically explaining a terminal region on which adriving circuit chip is mounted in a FCA method.

FIG. 87 is a plan view for schematically explaining a terminal regionwhen a method in which electricity is supplied to a flexible printedcircuit board or the like from a reference potential generation circuitdisposed in a control circuit of the liquid crystal display device isadopted.

FIG. 88 is a schematic plan view of the liquid crystal display devicefor explaining a first example in which a feeding terminal to areference electrode is formed.

FIG. 89 is a schematic plan view of the liquid crystal display devicefor explaining a second example in which a feeding terminal to areference electrode is formed.

FIG. 90 is a cross-sectional view of an essential part showing a portionA of FIG. 89 in an enlarged manner.

FIG. 91 is a schematic cross-sectional view of the liquid crystaldisplay device for explaining a third example in which a feedingterminal to a reference electrode is formed.

FIG. 92 is a cross-sectional view of an essential part showing thefeeding terminal portion of FIG. 91 in an enlarged manner.

FIG. 93 is a schematic cross-sectional view of the liquid crystaldisplay device for explaining a fourth example in which a feedingterminal to a reference electrode is formed.

FIG. 94 is a schematic cross-sectional view of a liquid crystal displaydevice for explaining a constitutional example of an outer periphery ofan effective display region when an organic insulation layer formed onthe first substrate is constituted of color filters.

FIG. 95 is a schematic cross-sectional view of a liquid crystal displaydevice for explaining another constitutional example of the outerperiphery of the effective display region when the organic insulationlayer formed on the first substrate is constituted of color filters.

FIG. 96 is a schematic cross-sectional view of a liquid crystal displaydevice for explaining a constitutional example in which color filtersare formed on all of a seal, an outer peripheral portion thereof and aneffective display region.

FIG. 97 is an explanatory view of an alignment method when drivingcircuits are mounted on various lead terminals and feeding terminalswhich are formed on the first substrate.

FIG. 98 is a schematic cross-sectional view of a liquid crystal displaydevice which is configured to prevent electrolytic corrosion of areference electrode layer formed on the first substrate.

FIG. 99 is a schematic plan view for explaining an example in whichcolor filters are formed when an organic insulation layer which isformed on the first substrate is constituted of the color filters.

FIG. 100 is a schematic plan view for explaining a constitutionalexample when an organic insulation layer which is formed on the firstsubstrate is constituted of color filters.

FIG. 101 is a schematic plan view for explaining another constitutionalexample when an organic insulation layer which is formed on the firstsubstrate is constituted of color filters.

FIG. 102 is a schematic plan view for explaining still anotherconstitutional example when an organic insulation layer which is formedon the first substrate is constituted of color filters.

FIG. 103 is a schematic cross-sectional view showing an example ofarrangement when the liquid crystal display device of the presentinvention is used as a transmission-type display module.

FIG. 104 is a schematic cross-sectional view for explaining anotherexample of arrangement when the liquid crystal display device of thepresent invention is used as transmission-type display module.

FIG. 105 is a schematic cross-sectional view for explaining an exampleof arrangement when the liquid crystal display device of the presentinvention is used as a reflection-type display module.

FIG. 106 is a schematic cross-sectional view for explaining anotherexample of arrangement when the liquid crystal display device of thepresent invention is used as a reflection-type display module.

FIG. 107 is a schematic cross-sectional view for explaining stillanother example of arrangement when the liquid crystal display device ofthe present invention is used as a reflection-type display module.

FIG. 108 is a schematic cross-sectional view for explaining stillanother example of arrangement when the liquid crystal display device ofthe present invention is used as a reflection-type display module.

FIG. 109 is a schematic cross-sectional view for explaining stillanother example of arrangement when the liquid crystal display device ofthe present invention is used as a reflection-type display module.

FIG. 110 is a schematic cross-sectional view for explaining an exampleof arrangement when the liquid crystal display device of the presentinvention is used as a transmission/reflection-type display module.

FIG. 111 is a schematic cross-sectional view for explaining anotherexample of arrangement when the liquid crystal display device of thepresent invention is used as a transmission/reflection-type displaymodule.

EXPLANATION OF SYMBOLS

SUB1 . . . first substrate, SUB2 . . . second substrate, CF . . . colorfilter, BM . . . black matrix, CT . . . common electrode (or counterelectrode), LC . . . liquid crystal (or liquid crystal layer), AL . . .orientation film, PAS . . . passivation layer, O-PAS(O-PAS1, O-PAS2) . .. organic insulation layer (first organic insulation layer, secondorganic insulation layer), SD1 . . . source electrode, SD2 . . . drainelectrode, DL . . . drain line (or drain line layer), GL . . . gate line(or gate line layer), GI . . . gate insulation layer, SM . . . metalshield, ST . . . reference electrode (or reference electrode layer), PX. . . pixel electrode (or pixel electrode layer), TH (TH1, TH2) . . .through hole, AS . . . semiconductor layer, Cstg . . . holding capacityor a storage capacity, NGI . . . gate insulation layer removed region,OC . . . overcoat layer, TED . . . second reference electrode, ML . . .metal layer, XP . . . organic insulation layer removed region, CT/ST . .. counter/reference electrode layer, BL . . . backlight, FL . . . frontlight

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present invention are explained in detailhereinafter in conjunction with drawings which show the embodiments.

FIG. 1 is a plan view of the vicinity of one pixel of a vertical fieldtype liquid crystal display device for schematically explaining thepixel constitution of the first embodiment of the present invention. Inthe drawings, reference symbol PX indicates a pixel electrode, DLindicates drain lines (video signal lines or data lines), GL indicatesgate lines (scanning lines), SM indicates a light shielding film (metalshield) which performs light shielding between the pixel electrode andthe drain line, ST indicates a reference electrode layer (also referredto as a conductive layer), SD1 indicates a source electrode, SD2indicates a drain electrode, AS indicates a semiconductor layer, and THindicates a through hole. Here, the above-mentioned gate lines, drainlines and respective electrodes are referred to as electrode layers whenthey are explained in conjunction with cross sections.

FIG. 2 is a cross-sectional view taken along a line I-I in FIG. 1 andFIG. 3 is also a cross-sectional view taken along a line II-II inFIG. 1. Reference symbol SUB1 indicates a first substrate, ST indicatesa reference electrode layer, O-PAS indicates an organic insulationlayer, PAS indicates a passivation layer, AL indicates orientationfilms, CT indicates a common electrode, CF indicates color filters, BMindicates a black matrix, and SUB2 indicates a second substrate.

In FIG. 1 to FIG. 3, in the liquid crystal display device, liquidcrystal (also referred to as a liquid crystal layer hereinafter) LC isfilled in a gap defined between the first substrate SUB1 and the secondsubstrate SUB2 which face each other in an opposed manner. On an innersurface of the first substrate SUB1, a plurality of gate lines GL whichextend in the first direction and are arranged parallel to each otherand a plurality of drain lines GL which extend in the second directioncrossing the gate lines and are arranged parallel to each other areformed.

Thin film transistors TFT which constitute switching elements areprovided to crossing portions of the gate lines GL and drain lines DL.Each thin film transistor TFT is constituted of the gate electrode whichis formed of the gate line GL, the drain electrode SD2 which extendsfrom the drain line DL, the semiconductor layer AS and the sourceelectrode SD1. In the embodiment described hereinafter, the explanationof the thin film transistor TFT is omitted.

The source electrode SD1 of the thin film transistor TFT is connected tothe pixel electrode layer PX via the through hole TH. The pixelelectrode layer PX is formed on the substantially whole portion of apixel region thus constituting a display region of the liquid crystaldisplay device. A multi-layered portion which forms the gate line GL,the drain line DL, the thin film transistor TFT and the pixel electrodePX including the pixel regions of the first substrate SUB1 is referredto as an electrode forming layer. Between this electrode forming layerand the first substrate side SUB1, the reference electrode layer STwhich insulates the electrode forming layer with the organic insulationlayer O-PAS is provided.

Here, including respective embodiments which will be explained later, aninorganic insulation layer may be used in place of the organicinsulation layer as O-PAS. By adopting the organic insulation layer, theparasitic capacity between the reference electrode layer and the gateline GL as well, as the drain line DL can be further reduced.

With respect to the above-mentioned electrode forming layer, above theorganic insulation layer O-PAS, the gate line layer GL, the gateinsulation layer GI, the drain line layer DL, the thin film transistorTFT, the passivation layer PAS and the pixel electrode layer PX areformed in this order. Then, a holding capacity of the pixel (so-calledCstg) is formed between the pixel electrode layer PX and the referenceelectrode layer ST. That is, the holding capacity is formed between thepixel electrode layer PX and the reference electrode layer ST using thepassivation layer PAS, the gate insulation layer GI and the organicinsulation layer O-PAS as dielectrics. The reference electrode layer STis formed over a wide area such that the reference electrode layer STcovers the whole pixel region.

As material of the organic insulation layer O-PAS, polysilazane can beused, for example. This material is coated using a SOG (Spin-On-Glass)method. The organic film material having low dielectric constant iseffective for reducing the parasitic capacitance between lines. Forexample, various organic material such as, polyimide, polyamide,polyimide amide, acrylic resin, polyacrylic resin and benzocyclobutenecan be used. Further, since it is necessary to make thetransmission-type liquid crystal display device have the sufficientlight transmitting characteristics, it is desirable to increase thelight transmissivity. It is effective to utilize existing materiallayers to effectively enhance the light transmissivity. That is, whenthe color filter layers are utilized as the above-mentioned organicinsulation layer, the light transmissivity is hardly impeded. To reducethe formation process of the organic insulation layer, it is desirablethat the layer material has photosensitivity. The same goes forrespective embodiments described later with respect to this point.

This is because that with the constitution which forms the through holebelow the gate insulation layer, the number of photolithographyprocesses can be reduced. Further, when the through hole is formed inthe organic insulation layer at a position equal to the position of thethrough hole formed in the gate insulation layer, at the time of formingthe thorough hole from the gate insulation layer or the insulation layerarranged above the gate insulation layer, patterning or collectiveforming which uses the upper insulation layer as a mask can be adoptedand hence, it is not always necessary to make the layer materialphotosensitive. However, products of various constitutions are usuallymanufactured using the same process and the same material and hence, toproduce a large kinds of products using the same manufacturing line, itis desirable to use material having photosensitivity. The same goes forrespective embodiments which will be explained later with respect tothis point as well.

Further, the film thickness of the organic insulation layer O-PAS can beeasily set for each constitution by performing simulation based ondisclosed contents of embodiments described later by those who areskilled in the art. That is, the film thickness can be calculated basedon characteristics curves obtained from values on the planar structureor the cross-sectional structure of the substrates, the dielectricconstant of the organic insulation layer and the like. By utilizing thecalculated film thickness, the actual film thickness can be set byselecting the film thickness for each product or the range correspondingto the design concept with respect to the wiring resistance, theperformance of peripheral driving circuits, using liquid crystalmaterial, the target quality and the like. The same goes for respectiveembodiment which will be explained later.

Due to such a constitution, the feeding resistance with respect to theholding capacity is largely reduced so that it is possible to obtain theliquid crystal display device which satisfies both of the enhancement ofthe numerical aperture of the pixel and the assurance of the holdingcapacity. Since it is unnecessary to provide the feeding line to thepixel region, the numerical aperture of the pixel can be enhanced.Further, storage capacities can be formed by the passivation layerformed between the pixel electrode and the reference electrode layer,the gate insulation layer and the organic insulation layer whichexhibits the small dielectric constant. Compared to a case in which onlythe organic insulation layer is formed, the distance from the liquidcrystal layer to the reference electrode layer can be largely increasedand hence, the influence of the electric field of the referenceelectrode layer to the electric field for driving the liquid crystal canbe reduced.

Further, in this embodiment, the reference electrode layer ST may beconfigured such that the reference electrode layer ST extends parallelto the extending direction of the gate line GL and is overlapped to theregion where the pixel electrode is formed. Due to such a constitution,the capacity between the gate line GL and the reference electrode layercan be reduced so that the increase of the parasitic capacity issuppressed and the potential can be stabilized.

FIG. 4 is a plan view of the vicinity of one pixel of a vertical fieldtype liquid crystal display device for schematically explaining thepixel constitution of the second embodiment of the present invention,FIG. 5 is a cross-sectional view taken along a line I-I in FIG. 4, andFIG. 6 is a cross-sectional view taken along a line II-II in FIG. 4.Reference symbols in the drawings which are equal to those of theprevious embodiment indicate identical functioning portions.

In this embodiment, the reference electrode layer ST has a region whichincludes regions where the gate line layer GL, the drain line DL and thepixel electrode layer PX of the first substrate SUB1 are formed. Theholding capacity is formed between the pixel electrode layer PX and thereference electrode layer ST. According to this embodiment, since thereference electrode layer ST is formed below the gate line layer GL, itis desirable to set the thickness of the organic insulation layer O-PASto equal to or more than 1 μm, for example, by taking the parasiticcapacity of both electrode layers into account.

Due to such a constitution, in addition to advantageous effects similarto those of the first embodiment, since the reference electrode layer STis formed of a so-called matted electrode, the feeding resistance can befurther reduced and the limitation imposed on the feeding direction canbe eliminated.

FIG. 7 is a plan view of the vicinity of one pixel of a vertical fieldtype liquid crystal display device for schematically explaining thepixel constitution of the third embodiment of the present invention andFIG. 8 is a cross-sectional view taken along a line I-I in FIG. 7.Reference symbols in the drawings which are equal to those of theprevious embodiments indicate identical functioning portions. Withrespect to the pixel forming layer, over the organic insulation layerO-PAS, the gate line layer GL, the gate insulation layer GI, the drainline layer DL, the thin film transistor TFT, the passivation layer PASand the pixel electrode PX are formed in this order. The whole or aportion of the pixel electrode PX in the pixel region penetrates thepassivation layer PAS and is brought into contact with the gateinsulation layer GI.

Due to such a constitution of this embodiment, in addition to theadvantageous effects obtained by respective embodiments, the storagecapacity formed between the reference electrode layer ST and the pixelelectrode PX can be adjusted by the area of the pixel electrode PX whichpenetrates the passivation layer PAS.

FIG. 9 is a cross-sectional view taken along a line I-I in FIG. 8 of thevicinity of a pixel in a vertical field type liquid crystal displaydevice for schematically explaining the pixel constitution of the fourthembodiment of the present invention. Reference symbols in the drawingswhich are equal to those of the previous embodiments indicate identicalfunctioning portions.

With respect to the pixel forming layer, over the organic insulationlayer O-PAS, the gate line layer GL, the gate insulation layer GI, thedrain line layer DL, the thin film transistor TFT, the passivation layerPAS and the pixel electrode PX are formed in this order. The whole or aportion of the pixel electrode PX in the pixel region penetrates thepassivation layer PAS and the gate insulation layer GL and is broughtinto contact with the organic insulation layer O-PAS.

Due to such a constitution of this embodiment, the storage capacityformed between the reference electrode layer ST and the pixel electrodePX can be adjusted by the area of the pixel electrode PX whichpenetrates the passivation layer PAS and the gate insulation layer GI.

FIG. 10 is a plan view of the vicinity of one pixel of a vertical fieldtype liquid crystal display device for schematically explaining thepixel constitution of the fifth embodiment of the present invention.This embodiment is a modification of the above-mentioned fourthembodiment, wherein the gate insulation layer GI is eliminated at aportion within the region of the pixel electrode PX. Advantageouseffects obtained by this embodiment is similar to those obtained by thefourth embodiment. Further, due to devoid of the gate insulation layerGI, the transmissivity is enhanced.

FIG. 11 is a plan view of the vicinity of one pixel of a vertical fieldtype liquid crystal display device for schematically explaining thepixel constitution of the sixth embodiment of the present invention. Inthis embodiment, the thin film transistor TFT includes the sourceelectrode SD1 over the gate insulation layer GI, wherein the sourceelectrode SD1 is connected to the pixel electrode PX via the throughhole TH formed in the passivation layer PAS and a portion of the sourceelectrode SD1 is expanded to the inside of the region of the pixelelectrode PX. It is preferable to expand the source electrode SD1 as anextension portion SD1E which extends along the gate line GL or the drainline DL.

Due to the constitution of this embodiment, in addition to theadvantageous effects obtained by respective embodiments, it is possibleto adjust the storage capacity by changing the length or the width ofthe extension portion SD1E of the source electrode SD1, that is, bychanging the area of the source electrode SD1 which overlaps the pixelelectrode PX.

FIG. 12 is a plan view of the vicinity of one pixel of a vertical fieldtype liquid crystal display device for schematically explaining thepixel constitution of the seventh embodiment of the present invention,FIG. 13 is a cross-sectional view taken along a line I-I in FIG. 12, andFIG. 14 is a cross-sectional view taken along a line II-II in FIG. 12.Reference symbols in the drawings which are equal to those of theprevious embodiments indicate identical functioning portions.

With respect to the liquid crystal display device of this embodiment,between the electrode forming layer which is constituted of the gateline layer GL, the drain line layer DL, the thin film transistor TFT andthe pixel electrode PX including the pixel regions of the firstsubstrate SUB1 and the first substrate SUB1 side, the referenceelectrode layer ST which is insulated by the first organic insulationlayer O-PAS1 with respect to the electrode forming layer is provided.The pixel forming layer is configured such that the gate line layer GL,the gate insulation layer GI, the drain line layer DL, the thin filmtransistor TFT, the passivation layer PAS, the second organic insulationlayer O-PAS2 and the pixel electrode PX are formed over the organicinsulation layer O-PAS1 in this order. The holding capacity of the pixelis formed between the pixel electrode PX and the reference electrodelayer ST.

Due to such a constitution of this embodiment, the numerical aperture ofthe pixel is enhanced and the feeding resistance can be reduced becauseof the large area of the conductive layer. Further, when the organicinsulation layer is also formed over the switching element, it ispossible to overlap the pixel electrode and the drain line to each otherso that the numerical aperture is further enhanced. When the pixelelectrode and the drain line overlap each other, it is possible toeliminate a light shielding layer between the vicinity in the extensiondirection of the drain line and the pixel electrode so that thenumerical aperture is still further enhanced.

Further, the above-mentioned reference electrode layer ST is formed inthe extension direction of the gate line layer GL such that thereference electrode layer ST is arranged parallel to the gate line layerGL and overlaps the region where the pixel electrode layer PX is formed.Accordingly, the parasitic capacity between the gate line layer and theconductive layer is reduced and the potential can be made stable.

Still further, the reference electrode layer is provided to the regionof the above-mentioned first substrate SUB1 which includes the regionwhere the gate line layer GL, the drain line layer DL and the pixelelectrode layer PX are formed. Due to such a constitution, since thereference electrode layer ST is formed of a so-called matted electrode,the feeding resistance can be further reduced and the limitation imposedon the feeding direction can be eliminated.

FIG. 15 is a plan view of the vicinity of one pixel of a vertical fieldtype liquid crystal display device for schematically explaining thepixel constitution of the eighth embodiment of the present invention,FIG. 16 is across-sectional view taken along a line I-I in FIG. 15, andFIG. 17 is a cross-sectional view taken along a line II-II in FIG. 15.Reference symbols in the drawings which are equal to those of theprevious embodiments indicate identical functioning portions.

In this embodiment, the above-mentioned first organic insulation layeris constituted of the color filters CF. Accordingly, the holdingcapacity is formed by the organic insulation layer O-PAS, thepassivation layer PAS, the gate insulation layer DI and the color filterlayers CF which are formed between the pixel electrode layer PX and thereference electrode layer ST and hence, the increase of the parasiticcapacity between the reference electrode layer and the gate line as wellas the drain line can be suppressed. Further, since the color filterlayers CF are formed on the first substrate SUB1, the tolerance ofalignment of the first substrate SUB1 with the second substrate SUB2 isincreased whereby the numerical aperture of the pixel is enhanced andthe feeding resistance can be reduced due to large area of theconductive layer.

FIG. 18 is a cross-sectional view taken along a line I-I in FIG. 15 of avertical field type liquid crystal display device for schematicallyexplaining the pixel constitution of the ninth embodiment of the presentinvention and FIG. 19 is a cross-sectional view taken along a line II-IIin FIG. 18. Reference symbols in the drawings which are equal to thoseof the previous embodiments indicate identical functioning portions.

In the embodiment shown in FIG. 17, the black matrix BM which performslight-shielding of boundaries of the color filters CF is formed on thesecond substrate SUB2 side. In this embodiment, the black matrix BM isformed on the first substrate SUB1 side.

Further, in the eighth embodiment and the ninth embodiment, theabove-mentioned reference electrode layer ST is formed in the extensiondirection of the gate line layer GL such that the reference electrodelayer ST is arranged parallel to the gate line layer GL and overlaps theregion where the pixel electrode layer PX is formed.

Due to such a constitution, the parasitic capacity formed between thegate line layer GL and the reference electrode layer ST can be reduced.Further, it is possible to stabilize the potential.

Further, by forming the reference electrode layer ST as a so-calledmatted electrode which is provided to a region of the first substrateSUB1 which includes a region where the gate line layer GL, the drainline layer DL and the pixel electrode layer PX are formed, the feedingresistance can be further reduced and the limitation imposed on thefeeding direction can be eliminated.

Further, an overcoat layer which levels the color filter layers CF maybe formed between the color filter layers CF and the gate insulationlayer GI. Here, the reference electrode layer ST may be formed betweenthe color filter layers CF and the gate insulation layer GI.

FIG. 20 is a plan view of the vicinity of one pixel of a vertical fieldtype liquid crystal display device for schematically explaining thepixel constitution of the tenth embodiment of the present invention andFIG. 21 is a cross-sectional view taken along a line III-III in FIG. 20.Reference symbols in the drawings which are equal to those of theprevious embodiments indicate identical functioning portions.

In this embodiment, between the electrode forming layer which isconstituted of the gate line layer GL, the drain line layer DL, the thinfilm transistor TFT, and the pixel electrode layer PX including thepixel regions of the first substrate SUB1 and the first substrate sideSUB1, the first reference electrode layer ST which is insulated by thefirst organic insulation layer O-PAS1 with respect to the electrodeforming layer is formed. Further, over the first organic insulationlayer O-PAS1, the gate line layer GL, the gate insulation layer GI, thedrain line layer DL, the thin film transistor TFT, the passivation layerPAS, the second organic insulation layer O-PAS2, and the pixel electrodelayer PX are formed in this order. A capacitive electrode layer TEDwhich is connected to the pixel electrode PX is formed between thesecond organic insulation layer O-PAS2 and the passivation layer PAS.

FIG. 22 is a cross-sectional view taken along a line III-III in FIG. 20for schematically explaining the pixel constitution of the eleventhembodiment of the present invention. Reference symbols in the drawingswhich are equal to those of the previous embodiments indicate identicalfunctioning portions. In this embodiment, the capacitive electrode layerTED shown in FIG. 21 is formed above the gate insulation layer GI andbelow the second organic insulation layer O-PAS2.

FIG. 23 is a cross-sectional view taken along a line III-III in FIG. 20for schematically explaining the pixel constitution of the twelfthembodiment of the present invention. Reference symbols in the drawingswhich are equal to those of the previous embodiments indicate identicalfunctioning portions. In this embodiment, the capacitive electrode layerTED shown in FIG. 21 or FIG. 22 is formed above the first organicinsulation layer O-PAS1 and below the gate insulation layer GI.

Due to the constitutions of the above-mentioned tenth, eleventh andtwelfth embodiments, the numerical aperture of the pixel can be enhancedand the feeding resistance can be reduced because of the large area ofconductive layer. Further, the storage capacity can be adjusted by thearea and shape of the capacitive electrode layer TED. Further, when theorganic insulation layer is also formed above the thin film transistor,it is possible to make the pixel electrode and the drain line overlapeach other so that the numerical aperture can be further enhanced. Whenthe pixel electrode and the drain line overlap each other, a lightshielding layer formed between the vicinity in the extension directionof the drain line and the pixel electrode can be eliminated so that thenumerical aperture can be further enhanced.

Here, the first reference electrode layer ST can be formed in theextension direction of the gate line layer GL such that the firstreference electrode layer ST is arranged parallel to the gate line layerGL and overlaps the region where the pixel electrode layer PX is formed.Due to such a constitution, the parasitic capacity formed between thegate line layer GL and the first reference electrode layer ST can bereduced whereby the increase of storage capacity can be suppressed orthe potential can be stabilized.

Further, the first reference electrode layer ST may be formed on aregion of the first substrate SUB1 which includes the region where thegate line layer GL, the drain line layer DL and the pixel electrodelayer PX are formed. Due to such a constitution, since the firstreference electrode layer ST is constituted of a so-called mattedelectrode, the feeding resistance is further reduced and the limitationimposed on the feeding direction can be eliminated.

FIG. 24 is a plan view of the vicinity of one pixel of a vertical fieldtype liquid crystal display device for schematically explaining thepixel constitution of the thirteenth embodiment of the present inventionand FIG. 25 is a cross-sectional view taken along a line III-III in FIG.24. Reference symbols in the drawings which are equal to those of theprevious embodiments indicate identical functioning portions. In thisembodiment, for example, the capacitive electrode layer TED explained inconjunction with FIG. 20 to FIG. 23 is formed between the passivationlayer PAS and the second organic insulation layer O-PAS in the pixelregion and is connected to the pixel electrode layer PX via the throughhole TH2.

That is, the thin film transistor TFT includes the source electrodewhich is connected to the pixel electrode PX via the through hole TH1formed in the passivation layer PAS on the gate insulation layer GI, andthe capacitive electrode layer TED is connected to the source electrodeSD1 and is provided to the region where the pixel electrode PX isformed.

Due to such a constitution, the holding capacity can be adjusted bychanging the size of the above-mentioned capacitive electrode layer TED.Here, the first organic insulation layer O-PAS may be formed of colorfilters.

Due to such a constitution, the numerical aperture of the pixel can beenhanced and the feeding resistance can be reduced because of the largearea of the conductive layer. Further, when the holding capacity isformed by the organic insulation layer O-PAS having small dielectricconstant, the passivation layer PAS, the gate insulation layer GI andthe color filter layer CF formed between the pixel electrode PX and thereference electrode layer ST, the increase of parasitic capacity can besuppressed. Further, since the color filter layers CF are formed on thefirst substrate SUB1, the tolerance of alignment of the first substrateSUB1 with the second substrate SUB2 can be increased.

FIG. 26 is a cross-sectional view taken along a line III-III in FIG. 24of the vicinity of one pixel of a vertical field type liquid crystaldisplay device for schematically explaining the pixel constitution ofthe fourteenth embodiment of the present invention. Reference symbols inthe drawings which are equal to those of the previous embodimentsindicate identical functioning portions. In this embodiment, thecapacitive electrode layer TED is provided over the gate insulationlayer GI. The pixel electrode PX is connected to the capacitiveelectrode layer TED via the through hole TH2 formed in the secondorganic insulation layer O-PAS2 and the passivation layer PAS.

FIG. 27 is a cross-sectional view taken along a line III-III in FIG. 24of the vicinity of one pixel of a vertical field type liquid crystaldisplay device for schematically explaining the pixel constitution ofthe fifteenth embodiment of the present invention. Reference symbols inthe drawings which are equal to those of the previous embodimentsindicate identical functioning portions. In this embodiment, thecapacitive electrode layer TED is provided over the first organicinsulation layer O-PAS. The pixel electrode PX is connected to thecapacitive electrode layer TED via the through hole TH2 which is formedsuch that the through hole TH2 penetrates the second organic insulationlayer O-PAS2, the passivation layer PAS and the gate insulation layerGI.

Due to the constitutions of the above-mentioned thirteenth to fifteenthembodiments, the holding capacity formed between the conductive layerand the pixel electrode PX can be adjusted by changing the area of thecapacitive electrode layer TED.

Further, the first organic insulation layer O-PAS1 in the thirteenth tofifteenth embodiments may be formed of color filters.

Due to such a constitution, the numerical aperture of the pixel can beenhanced and the feeding resistance can be reduced because of the largearea of the conductive layer. Further, when the color filter layers CFare formed on the first substrate SUB1, the tolerance of alignment ofthe first substrate SUB1 with the second substrate SUB2 can beincreased.

FIG. 28 is a plan view of the vicinity of one pixel of a vertical fieldtype liquid crystal display device for schematically explaining thepixel constitution of the sixteenth embodiment of the present inventionand FIG. 29 is a cross-sectional view taken along a line III-III in FIG.28. Reference symbols in the drawings which are equal to those of theprevious embodiments indicate identical functioning portions. In thisembodiment, between the electrode forming layer which is constituted ofthe gate line GL, the drain line DL, the switching element or thin filmtransistor TFT, and the pixel electrode PX including the pixel regionsof the first substrate SUB1 and the first substrate SUB1 side, the firstreference electrode layer ST which is insulated by the organicinsulation layer O-PAS with respect to the electrode forming layer isformed.

Further, with respect to the above-mentioned electrode forming layer,over the above-mentioned organic insulation layer O-PAS, the gate linelayer GL, the gate insulation layer GI, the drain line layer DL, thethin film transistor TFT, the passivation layer PAS, and the pixelelectrode layer PX are formed in this order. A capacitive electrodelayer TED which is connected to the pixel electrode layer PX is formedbetween the organic insulation layer O-PAS and the passivation layerPAS. Still further, the holding capacity of the pixel is formed betweenthe pixel electrode layer PX and the first reference electrode layer STas well as the capacitive electrode layer TED.

As shown in FIG. 29, the capacitive electrode layer TED is providedabove the gate insulation layer GI and the source electrode SD1 isconnected to the capacitive electrode layer TED. The switching elementTFT includes the source electrode SD1 which is connected to the pixelelectrode PX via the through hole TH formed in the passivation layer PASover the gate insulation layer GI, and the capacitive electrode layerTED is formed in the pixel region in such a manner that the capacitiveelectrode layer TED is connected to the source electrode SD1.

Due to such a constitution, the storage capacity can be adjusted bychanging the size of the above-mentioned capacitive electrode layer TED.Further, the organic insulation layer O-PAS may be formed of colorfilter layers.

Due to such a constitution of this embodiment, the numerical aperture ofthe pixel can be enhanced and the feeding resistance can be reducedbecause of the large area of the conductive layer. The holding capacitycan be adjusted by changing the size of the capacitive electrode layerTED. Further, when the color filter layers CF are formed on the firstsubstrate SUB1, the tolerance of alignment of the first substrate SUB1with the second substrate SUB2 can be increased.

FIG. 30 is a cross-sectional view taken along a line III-III in FIG. 28of the vicinity of one pixel of a vertical field type liquid crystaldisplay device for schematically explaining the pixel constitution ofthe seventeenth embodiment of the present invention. Reference symbolsin the drawings which are equal to those of the previous embodimentsindicate identical functioning portions. In this embodiment, thecapacitive electrode layer TED is provided over the organic insulationlayer O-PAS and the source electrode SD1 is connected to the capacitiveelectrode layer TED via the through hole TH which penetrates the gateinsulation layer GI.

Due to such a constitution, the holding capacity formed between thecapacitive electrode layer TED and the pixel electrode PX can beadjusted based on the area of pixel electrode PX which penetrates thepassivation layer PAS and the gate insulation layer GI. Further, theorganic insulation layer O-PAS may be formed of color filter layers.

Due to such a constitution of this embodiment, the numerical aperture ofthe pixel can be enhanced and the feeding resistance can be reducedbecause of the large area of the first reference electrode layer.Further, when the organic insulation layer is formed of color filterlayers, the tolerance of alignment of the first substrate SUB1 with thesecond substrate SUB2 can be increased.

FIG. 31 is a plan view of the vicinity of one pixel of a vertical fieldtype liquid crystal display device for schematically explaining thepixel constitution of the eighteenth embodiment of the present inventionand FIG. 32 is a cross-sectional view taken along a line III-III in FIG.31. Reference symbols in the drawings which are equal to those of theprevious embodiments indicate identical functioning portions. In thisembodiment, the capacitive electrode layer TED is provided over the gateinsulation layer GI and the pixel electrode layer PX is connected to thecapacitive electrode layer TED via the through hole TH2 which penetratesthe passivation layer PAS. Further, the organic insulation layer O-PASmay also be formed of color filter layers.

Due to such a constitution of this embodiment, the holding capacityformed between the first reference electrode layer ST and the pixelelectrode layer PX can be adjusted by changing the area of thecapacitive electrode layer TED. Further, the organic insulation layerO-PAS may be also formed of color filter layers.

FIG. 33 is a cross-sectional view taken along a line III-III in FIG. 31of the vicinity of one pixel of a vertical field type liquid crystaldisplay device for schematically explaining the pixel constitution ofthe nineteenth embodiment of the present invention. Reference symbols inthe drawings which are equal to those of the previous embodimentsindicate identical functioning portions. In this embodiment, thecapacitive electrode layer TED is provided over the organic insulationlayer O-PAS and the pixel electrode layer PX is connected to thecapacitive electrode layer TED via the through hole TH2 which penetratesthe passivation layer PAS and the gate insulation layer GI.

Due to such a constitution of this embodiment, the holding capacityformed between the first reference electrode layer ST and the pixelelectrode layer PX can be adjusted by changing the area of thecapacitive electrode layer TED. Further, the organic insulation layerO-PAS may be also formed of color filter layers.

FIG. 34 is a plan view of the vicinity of one pixel of a vertical fieldtype liquid crystal display device for schematically explaining thepixel constitution of the twentieth embodiment of the present inventionand FIG. 35 is a cross-sectional view taken along a line III-III in FIG.34. Reference symbols in the drawings which are equal to those of theprevious embodiments indicate identical functioning portions. In thisembodiment, the capacitive electrode layer TED is provided over thefirst organic insulation layer O-PAS and the capacitive electrode layerTED is connected to the first reference electrode layer ST via thethrough hole TH2 which penetrates the first organic insulation layerO-PAS1.

Due to such a constitution, the storage capacity is adjusted by changingthe area of capacitive electrode layer TED which is connected to thefirst reference electrode layer ST. Further, when color filter layers CFare formed on the first substrate SUB1, the tolerance of alignment ofthe first substrate SUB1 with the second substrate SUB2 can beincreased.

FIG. 36 is a cross-sectional view taken along a line III-III in FIG. 34of the vicinity of one pixel of a vertical field type liquid crystaldisplay device for schematically explaining the pixel constitution ofthe twenty-first embodiment of the present invention. Reference symbolsin the drawings which are equal to those of the previous embodimentsindicate identical functioning portions. In this embodiment, thecapacitive electrode layer TED is provided over the gate insulationlayer GI and the capacitive electrode layer TED is connected to thefirst reference electrode layer ST via the through hole TH2 whichpenetrates the gate insulation layer GI.

Due to such a constitution of this embodiment, the storage capacity canbe adjusted by changing the area of the capacitive electrode layer whichis connected to the first reference electrode layer ST. Further, whenthe color filter layers CF are formed on the first substrate SUB1, thetolerance of alignment of the first substrate SUB1 with the secondsubstrate SUB2 can be increased.

FIG. 37 is a cross-sectional view taken along a line III-III in FIG. 34of the vicinity of one pixel of a vertical field type liquid crystaldisplay device for schematically explaining the pixel constitution ofthe twenty-second embodiment of the present invention. Reference symbolsin the drawings which are equal to those of the previous embodimentsindicate identical functioning portions. In this embodiment, thecapacitive electrode layer TED is provided over the passivation layerPAS and the capacitive electrode layer TED is connected to the firstreference electrode layer ST via the through hole TH2 which penetratesthe passivation layer PAS, the gate insulation layer GI and the firstorganic insulation layer O-PAS1.

Due to such a constitution of this embodiment, the storage capacitywhich is formed between the conductive layer and the pixel electrode PXcan be adjusted by changing the area of the capacitive electrode layerTED which is connected to the first reference electrode layer ST.Further, when the color filter layers CF are formed on the firstsubstrate SUB1, the tolerance of alignment of the first substrate SUB1with the second substrate SUB2 can be increased.

Further, due to such a constitution of this embodiment, the numericalaperture can be enhanced and the feeding resistance can be reducedbecause of the large area of the conductive layer. Further, when thefirst organic insulation layer O-PAS1 is formed of color filters, thetolerance of alignment of the first substrate SUB1 with the secondsubstrate SUB2 can be increased.

FIG. 38 is a plan view of the vicinity of one pixel of a vertical fieldtype liquid crystal display device for schematically explaining thepixel constitution of the twenty-third embodiment of the presentinvention and FIG. 39 is a cross-sectional view taken along a lineIII-III in FIG. 38. Reference symbols in the drawings which are equal tothose of the previous embodiments indicate identical functioningportions. In this embodiment, the capacitive electrode layer TED isprovided over the gate insulation layer GI and the capacitive electrodelayer TED is connected to the first reference electrode layer ST via thethrough hole TH2 which penetrates the gate insulation layer GI and theorganic insulation layer O-PAS.

Due to such a constitution of this embodiment, the holding capacitywhich is formed between the first reference electrode layer ST and thepixel electrode layer PX can be adjusted by changing the area of thecapacitive electrode layer TED which is connected to the first referenceelectrode layer ST. Further, when the color filter layers CF are formedon the first substrate SUB1, the tolerance of alignment of the firstsubstrate SUB1 with the second substrate SUB2 can be increased.

FIG. 40 is a cross-sectional view taken along a line III-III in FIG. 38of the vicinity of one pixel of a vertical field type liquid crystaldisplay device for schematically explaining the pixel constitution ofthe twenty-fourth embodiment of the present invention. Reference symbolsin the drawings which are equal to those of the previous embodimentsindicate identical functioning portions. In this embodiment, thecapacitive electrode layer TED is provided over the organic insulationlayer O-PAS and the capacitive electrode layer TED is connected to thefirst reference electrode layer ST via the through hole TH2 whichpenetrates the organic insulation layer O-PAS.

Due to such a constitution of this embodiment, the holding capacitywhich is formed between the first reference electrode layer ST and thepixel electrode layer PX can be adjusted by changing the area of thecapacitive electrode layer TED which is connected to the first referenceelectrode layer ST. Further, when the color filter layers CF are formedon the first substrate SUB1, the tolerance of alignment of the firstsubstrate SUB1 with the second substrate SUB2 can be increased.

FIG. 41 is a cross-sectional view taken along a line III-III in FIG. 38of the vicinity of one pixel of a vertical field type liquid crystaldisplay device for schematically explaining the pixel constitution ofthe twenty-fifth embodiment of the present invention. Reference symbolsin the drawings which are equal to those of the previous embodimentsindicate identical functioning portions. In this embodiment, thecapacitive electrode layer TED is provided over the gate insulationlayer GI and, at the same time, the second capacitive electrode layerTEDD is formed on the organic insulation layer O-PAS. The pixelelectrode PX is connected to the capacitive electrode layer TED by wayof the through hole TH2 formed in the passivation layer PAS and, at thesame time, the second capacitive electrode layer TEDD is connected tothe first reference electrode layer ST via through hole TH3 formed inthe organic insulation layer O-PAS.

Due to such a constitution of this embodiment, the holding capacitywhich is formed between the first reference electrode layer ST and thepixel electrode layer PX can be adjusted by changing the area of thecapacitive electrode layer TED and the area of the second capacitiveelectrode layer TEDD. Further, when the color filter layers CF areformed on the first substrate SUB1, the tolerance of alignment of thefirst substrate SUB1 with the second substrate SUB2 can be increased.

FIG. 42 is a plan view of the vicinity of one pixel of a vertical fieldtype liquid crystal display device for schematically explaining thepixel constitution of the twenty-sixth embodiment of the presentinvention and FIG. 43 is a cross-sectional view taken along a lineIII-III in FIG. 42. Reference symbols in the drawings which are equal tothose of the previous embodiments indicate identical functioningportions. This embodiment describes a case in which the capacitiveelectrode layer TED in the above-mentioned respective embodiments isprovided to the first substrate SUB1 and the organic insulation layer isformed of the color filter layers CF.

When the color filter layers CF are formed on the first substrate SUB1,since the color filters CF are not present at portions of the firstsubstrate SUB1 corresponding to the through hole TH2, leaking of lightis generated at this portions. To prevent such leaking of light, ametal-shielding film ML is formed over the through hole TH2 whichconnects the capacitive electrode TED with the first reference electrodelayer ST and the capacitive electrode layer TED is connected to thefirst reference electrode layer ST through the metal light-shieldingfilm ML.

FIG. 44 is a cross-sectional view taken along a line III-III in FIG. 42of the vicinity of one pixel of a vertical field type liquid crystaldisplay device for schematically explaining the pixel constitution ofthe twenty-seventh embodiment of the present invention. In thisembodiment, the metal light-shielding film ML according to theabove-mentioned twenty-sixth embodiment is provided over the capacitiveelectrode layer TED.

FIG. 45 is a plan view of the through hole TH2 and the metallight-shielding film ML according to the twenty-sixth embodiment or thetwenty-seventh embodiment of the present invention. Respective sides ofthe metal light-shielding film ML are larger than corresponding sides ofan opening portion of the through hole TH2 and are set to the size of atleast equal to or more than 1 μm. Here, the same goes for a case inwhich an overcoat layer is formed on the color filter layers CF.

FIG. 46 is a cross-sectional view of an essential part served forexplaining the twenty-eighth embodiment of the present invention and forshowing the cross-sectional structure of the through hole TH1 and themetal light-shielding film ML. In this embodiment, color filters CF areused as the organic insulation layer, the capacitive electrode layer TEDis formed on the gate insulation layer which is, in turn, formed on thesame layer as the source electrode SD1, and the source electrode SD1 isformed of the metal light-shielding film ML. This provision is made tocope with leaking of light at the through hole portion using the metallight-shielding film formed on the through hole portion. One example ofsuch a constitution is explained taking a TH2 portion in FIG. 42 as anexample. It is needless to say that other through holes may be used forperforming light-shielding of through hole portions.

In FIG. 46 (a), the metal light-shielding film ML is formed such thatthe metal light-shielding film ML penetrates the through hole TH1 fromthe source electrode SD1 and is connected to the first referenceelectrode layer ST such that the capacitive electrode TED is formed overthe source electrode SD1. In FIG. 46 (b), after forming the capacitiveelectrode layer TED in the through hole TH2, the metal light-shieldingfilm ML is formed in the through hole TH1 from the source electrode SD1.In FIG. 46( c), after forming the metal light-shielding film ML in thethrough hole TH1, the first reference electrode layer ST is connected tothe reference electrode layer TED via the SD layer.

Further, in FIG. 46( d), the metal light-shielding film ML is formed inthe through hole TH and, after connecting the light-shielding metal filmML with the reference electrode layer ST, metal light-shielding film MLand the reference electrode layer TED are connected to each other.

In the above-mentioned respective embodiments, by forming the referenceelectrode layer (or the first reference electrode layer) ST in theextending direction of the gate line GL such that the layer is arrangedparallel to the gate line GL and overlaps the region where the pixelelectrode PX is formed, the increase of the parasitic capacity betweenthe gate line layer GL and the reference electrode layer (or the firstreference electrode layer) can be suppressed and the potential can bestabilized.

Further, in the above-mentioned respective embodiments, by forming thereference electrode layer (or the first reference electrode layer) ST inthe region of the first substrate SUB1 which includes the region wherethe gate line GL, the drain line DL and the pixel electrode PX areformed, the reference electrode layer ST is formed of a so-called mattedelectrode and hence, the feeding resistance can be further reduced andthe limitation imposed on the feeding direction can be eliminated.

Further, in the above-mentioned respective embodiments, by providing thelight-shielding layer ML which performs light-shielding between thevicinity in the extension direction of the drain line DL and the pixelelectrode PX, it is possible to prevent leaking of light between thedrain line DL and the pixel electrode PX.

FIG. 47 is a plan view of the vicinity of one pixel of an IPS typeliquid crystal display device for schematically explaining the pixelconstitution of the twenty-ninth embodiment of the present invention andFIG. 48 is a cross-sectional view taken along a line III-III in FIG. 47.Reference symbols in the drawings which are equal to those of theprevious embodiments indicate identical functioning portions. In thisembodiment, liquid crystal is inserted in a gap defined between a firstsubstrate SUB1 and a second substrate SUB2 which face each other in anopposed manner. On an inner surface of the first substrate SUB1, aplurality of gate lines GL which extend in the first direction and arearranged parallel to each other and a plurality of drain lines GL whichextend in the second direction which crosses the gate lines GL and arearranged parallel to each other, a plurality of thin film transistorswhich are arranged at crossing portions of the gate lines GL and thedrain lines DL, comb-shaped pixel electrodes PX which are driven by thethin film transistors TFT, and comb-shaped counter electrodes CT whichgenerate electric fields for driving pixels between the counterelectrodes CT and the pixel electrodes PX are formed.

The pixel electrodes PX and the counter electrodes CT may be formed onthe same layer.

Further, between an electrode forming layer which is constituted of thegate line GL, the drain line DL, the thin film transistor TFT and thepixel electrode PS including a pixel region of the first substrate SUB1and the first substrate SUB1 side, a reference electrode layer ST whichis insulated by an organic insulation layer O-PAS with respect to theelectrode forming layer is provided and holding capacity of the pixel isformed between the pixel electrode PX and the reference electrode layerST.

Further, the counter electrode CT is formed over the organic insulationlayer O-PAS and the counter electrode CT is connected to the referenceelectrode layer ST via a through hole TH formed in the organicinsulation layer O-PAS.

Due to such a constitution of this embodiment, it is possible to formthe sufficient holding capacity and hence, the image quality can bestabilized and enhanced. Further, since it is unnecessary to increasethe area of the pixel electrode PX for forming the holding capacity, thenumerical aperture can be enhanced. Still further, since the area of thereference electrode layer ST is large, the feeding resistance can bereduced.

FIG. 49 is a cross-sectional view taken along a line IV-IV in FIG. 47 ofthe vicinity of one pixel of the IPS type liquid crystal display devicefor schematically explaining the pixel constitution of the thirtiethembodiment of the present invention. The counter electrode CT is formedover a gate insulation layer GI and the counter electrode CT isconnected to the reference electrode layer ST via the through hole THformed in the gate insulation layer GI and the organic insulation layerO-PAS.

Due to such a constitution of this embodiment, holding capacity isformed between the pixel electrode PX and the reference electrode layerST via the organic insulation layer O-PAS having small dielectricconstant. Since it is unnecessary to increase the area of the pixelelectrode PX for forming the holding capacity, the numerical aperture isenhanced. Further, since the area of the reference electrode layer ST islarge, the feeding resistance can be reduced.

FIG. 50 is a cross-sectional view taken along a line IV-IV in FIG. 47 ofthe vicinity of one pixel of the IPS type liquid crystal display devicefor schematically explaining the pixel constitution of the thirty-firstembodiment of the present invention. In this embodiment, the counterelectrode CT is formed over a passivation layer PAS and the counterelectrode CT is connected to the reference electrode layer ST via athrough hole TH formed in the passivation layer PAS, the gate insulationlayer GI and the organic insulation layer O-PAS.

Due to such a constitution of this embodiment, holding capacity isformed between the pixel electrode PX and the reference electrode layerST via the organic insulation layer O-PAS having small dielectricconstant. Since it is unnecessary to increase the area of the pixelelectrode PX for forming the holding capacity, the numerical aperture isenhanced. Further, since the area of the reference electrode layer ST islarge, the feeding resistance can be reduced.

Further, in the above-mentioned twenty-ninth embodiment and thethirtieth embodiment, the reference electrode layer ST may be formed inthe extension direction of the gate line GL such that the referenceelectrode layer ST is arranged parallel to the gate line GL and overlapsthe region where the pixel electrode PX and the counter electrode CT areformed.

Due to such a constitution, the parasitic capacity formed between thegate line layer GL and the reference electrode layer ST can be reduced,the increase of the holding capacity is suppressed, and the potentialcan be stabilized.

Further, in the above-mentioned twenty-ninth embodiment and thethirtieth embodiment, the reference electrode layer ST may be formed ina region of the first substrate SUB1 which includes the region where thegate line layer GL, the drain line layer DL, the pixel electrode PX andthe counter electrode CT are formed.

Due to such a constitution, since the reference electrode layer ST isformed of a so-called matted electrode, the feeding resistance can befurther reduced and the limitation imposed on the feeding direction canbe eliminated. Further, by increasing a layer thickness of the organicinsulation layer O-PAS, the influence of the reference electrode layerST to the liquid crystal driving electric field can be reduced. Colorfilters may be used in place of the organic insulation layer O-PAS.Further, when an overcoat layer is formed over the color filters, it isdesirable to form the reference electrode layer ST below the colorfilter layer.

FIG. 51 is a plan view of the vicinity of one pixel of an IPS typeliquid crystal display device for schematically explaining the pixelconstitution of the thirty-second embodiment of the present inventionand FIG. 52 is a cross-sectional view taken along a line V-V in FIG. 51.In this embodiment, a counter electrode CT is formed over an organicinsulation layer O-PAS and extends to a neighboring pixel region bycrossing the drain line DL and is connected to a reference electrodelayer of the neighboring pixel region via a through hole TH formed inthe organic insulation layer O-PAS.

Due to such a constitution of this embodiment, even when the throughhole TH is insufficiently formed, feeding electricity is performedthrough the reference electrode layer ST from the neighboring pixelside.

FIG. 53 is a cross-sectional view taken along a line V-V in FIG. 51 ofthe vicinity of one pixel of an IPS type liquid crystal display devicefor schematically explaining the pixel constitution of the thirty-thirdembodiment of the present invention. In this embodiment, a counterelectrode CT is formed over a gate insulation layer GI and a capacitiveelectrode layer TED which crosses one drain line DL and extends to aneighboring pixel region is formed over the organic insulation layerO-PAS. The counter electrode layer CT is connected to a first referenceelectrode layer ST via a through hole TH formed in the gate insulationlayer GI and the organic insulation layer O-PAS.

Due to such a constitution of this embodiment, even when the throughhole TH is insufficiently formed, feeding of electricity is performedfrom the neighboring pixel side to the first reference electrode layerST through the capacitive electrode layer TED. Further, by forming thethrough holes which connect each counter electrode and each referenceelectrode in a plural number for every pixel, the reliability ofconnection between electrode layers can be enhanced.

FIG. 54 is a cross-sectional view taken along a line V-V in FIG. 51 ofthe vicinity of one pixel of an IPS type liquid crystal display devicefor schematically explaining the pixel constitution of the thirty-fourthembodiment of the present invention. In this embodiment, a counterelectrode CT is formed over a passivation layer PAS and a capacitiveelectrode layer TED which crosses one drain line DL and extends to aneighboring pixel region is formed over the organic insulation layerO-PAS. The counter electrode layer CT is connected to a first referenceelectrode layer ST via a through hole TH formed in the passivation layerPAS, the gate insulation layer GI and the organic insulation layerO-PAS.

Due to such a constitution of this embodiment, even when the throughhole TH is insufficiently formed, feeding of electricity is performedfrom the neighboring pixel side through the capacitive electrode layerTED.

FIG. 55 is a cross-sectional view taken along a line V-V in FIG. 51 ofthe vicinity of one pixel of an IPS type liquid crystal display devicefor schematically explaining the pixel constitution of the thirty-fifthembodiment of the present invention. In this embodiment, a color filterlayer CF is formed below the first reference electrode layer ST of thethirty-fourth embodiment shown in FIG. 54 and over the above-mentionedfirst substrate SUB1.

Due to such a constitution, in addition to the advantageous effectsobtained by the previous embodiment, the color filter layer CF isisolated from the liquid crystal layer due to the first referenceelectrode layer ST and hence, the contamination of the liquid crystaldue to constituent material of the color filter layer CF can beprevented.

FIG. 56 is a plan view of the vicinity of one pixel of an IPS typeliquid crystal display device for explaining a modification of theembodiments shown in FIG. 47 to FIG. 55. That is, the through holes THwhich connect the counter electrode CT and the reference electrode ST ofeach pixel are formed in a plural number for each pixel so that thereliability of connection between these electrode layers can beenhanced.

FIG. 57 is a plan view of the vicinity of one pixel of an IPS typeliquid crystal display device for schematically explaining the pixelconstitution of the thirty-sixth embodiment of the present invention andFIG. 58 is a cross-sectional view taken along a line VI-VI in FIG. 57.In this embodiment, a counter electrode CT is formed over an organicinsulation layer O-PAS such that the counter electrode CT is arrangedparallel to the extension direction of a gate line GL and extends over aneighboring pixel region. Further, in each pixel region, the counterelectrode CT is connected to a reference electrode ST in each pixelregion via a through hole TH formed in the organic insulation layerO-PAS.

Due to such a constitution, holding capacity is formed at a portionwhere the counter electrode CT and the pixel electrode PX overlap eachother and the gate insulation layer GI constitutes a dielectric of theholding capacity. This constitution is suitable for increasing theholding capacity.

FIG. 59 is a cross-sectional view taken along a line VI-VI in FIG. 57 ofthe vicinity of one pixel of an IPS type liquid crystal display devicefor schematically explaining the pixel constitution of thethirty-seventh embodiment of the present invention. In this embodiment,a counter electrode CT is formed over a gate insulation layer, forexample, and a capacitive electrode layer TED is formed over an organicinsulation layer O-PAS such that the capacitive electrode layer TED isarranged parallel to the extension direction of a gate line GL andextends over a pixel region disposed close to the organic insulationlayer O-PAS. In each pixel region, the counter electrode CT is connectedto a reference electrode layer ST via a through hole TH formed in theorganic insulation layer O-PAS and a gate insulation layer GI in apenetrating manner. Further, holding capacity is formed at a portionwhere the capacitive electrode layer TED and the pixel electrode layerPX overlap each other.

Due to such a constitution, the gate insulation layer GI constitutes adielectric of the holding capacity and forms a comb-shaped pixelelectrode.

FIG. 60 is a plan view of the vicinity of one pixel of a modified IPStype liquid crystal display device for schematically explaining thepixel constitution of the thirty-eighth embodiment of the presentinvention, FIG. 61 is a cross-sectional view taken along a line VII-VIIin FIG. 60, and FIG. 62 is across-sectional view taken along a lineVIII-VIII in FIG. 60. In this embodiment, a pixel electrode PX is formedover a gate insulation layer GI in a so-called herringbone shape. Asource electrode SD1 is formed over the gate insulation layer GI and apixel electrode overlaps the source electrode SD1. A counter electrodeCT is formed over an organic insulation layer O-PAS and is connected toa reference electrode layer ST via a through hole TH2 thus formingholding capacity between the counter electrode CT and theabove-mentioned pixel electrode PX.

Due to such a constitution of this embodiment, the gate insulation layerGI constitutes a dielectric of the holding capacity and hence, thereduction of holding capacity brought about by forming the pixelelectrode in a herringbone shape can be increased.

FIG. 63 is a cross-sectional view taken along a line VII-VII in FIG. 60of the vicinity of one pixel of a modified IPS type liquid crystaldisplay device for schematically explaining the pixel constitution ofthe thirty-ninth embodiment of the present invention. In thisembodiment, a source electrode SD1 is formed over a gate insulationlayer GI and is connected to a pixel electrode PX formed over apassivation layer PAS via a through hole TH1. This embodiment is similarto the embodiment shown in FIG. 61 with respect to other constitutions.

Due to such a constitution, the gate insulation layer GI constitutes adielectric of holding capacity.

FIG. 64 is a plan view of a thin film transistor TFT portion of amodified IPS type liquid crystal display device for schematicallyexplaining an essential part of the pixel constitution of the fortiethembodiment of the present invention. In this embodiment, holdingcapacity can be adjusted by changing an area of a source electrode SD1of the thin film transistor TFT formed over a gate insulation layer GI.

The holding capacity can be adjusted in other embodiments of the presentinvention using such a concept.

FIG. 65 is a plan view of the vicinity of one pixel of a modified IPStype liquid crystal display device for schematically explaining anessential part of the pixel constitution of the forty-first embodimentof the present invention and FIG. 66 is a cross-sectional view takenalong a line IX-IX in FIG. 65. In this embodiment, a pixel electrode PXis formed over a gate insulation layer GI in a so-called herringboneshape. A source electrode SD1 is formed over the gate insulation layerGI and a pixel electrode overlaps the source electrode SD1. A referenceelectrode is formed below an organic insulation layer O-PAS and thisreference electrode constitutes a reference/counter electrode layerST/CT which also functions as a counter electrode. Holding capacity isformed between the reference/counter electrode layer ST/CT and the pixelelectrode PX.

Due to such a constitution of this embodiment, it is possible to obtaina liquid crystal display device which can render the formation of thecounter electrode layer CT unnecessary, can largely reduce the feedingresistance with respect to the holding capacity and prevents thereduction of numerical aperture of the pixel.

Further, the reference/counter electrode layer ST/CT is formed in theextension direction of the gate line GL such that the reference/counterelectrode layer ST/CT is arranged parallel to the gate line GL, forexample, and overlaps a region where the pixel electrode PX is formed.

Due to such a constitution, it is unnecessary to provide an independentreference/counter electrode layer for every pixel so that capacitybetween the gate line layer GL and the reference/counter electrode layerST/CT can be reduced, the increase of parasitic capacity can besuppressed, and the potential can be stabilized.

Further, the reference/counter electrode layer ST/CT is formed over thewhole region of the first substrate SUB1 including a region where thegate line GL, the drain line DL and the pixel electrode PX are formed.

Due to such a constitution, the reference/counter electrode layer ST/CTconstitutes a so-called matted electrode and hence, feeding resistanceis further reduced and the limitation imposed on the feeding directioncan be eliminated.

FIG. 67 is a cross-sectional view taken along a line IX-IX in FIG. 65 ofthe vicinity of one pixel of a modified IPS type liquid crystal displaydevice for schematically explaining an essential part of the pixelconstitution of the forty-second embodiment of the present invention. Inthis embodiment, a pixel electrode PX is formed over a gate insulationlayer GI in a so-called herringbone shape. A source electrode SD1 isformed over the gate insulation layer GI and a pixel electrode overlapsthe source electrode SD1. This embodiment corresponds to a constitutionwhich is formed by wholly or partially removing an organic insulationlayer O-PAS below the pixel electrode PX from the constitution shown inFIG. 66.

Due to such a constitution, the strength of an electric field generatedbetween the pixel electrode PX and the reference/counter electrode layerST/CT can be increased so that the driving voltage can be reduced.

FIG. 68 is a plan view of the vicinity of one pixel of a modified IPStype liquid crystal display device for schematically explaining anessential part of the pixel constitution of the forty-third embodimentof the present invention and FIG. 69 is a cross-sectional view takenalong a line X-X in FIG. 68. In this embodiment, a counter electrodelayer CT is formed over an organic insulation layer O-PAS and aconnection line GLL which is arranged parallel to the extensiondirection of a gate line GL and is connected to a pixel electrode PXdisposed close to the counter electrode CT is formed over the counterelectrode layer CT.

FIG. 70 is a cross-sectional view taken along a line X-X in FIG. 68 ofthe vicinity of one pixel of a modified IPS type liquid crystal displaydevice for schematically explaining an essential part of the pixelconstitution of the forty-fourth embodiment of the present invention. Inthis embodiment, a connection line GLL which is arranged parallel to theextension direction of a gate line GL and is connected to a pixelelectrode layer PX disposed close to a counter electrode layer CT isformed between the counter electrode layer CT and an organic insulationlayer O-PAS.

Due to such constitutions of the forty-third embodiment and theforty-fourth embodiment, even when a through hole TH is formedinsufficiently, feeding of electricity is performed from a neighboringpixel side through a conductive layer. Further, by forming the throughholes TH which connect each counter electrode layer CT and the eachreference electrode ST in a plural number for every pixel, thereliability of connection between these electrode layers can beenhanced.

FIG. 71 is a plan view of the vicinity of one pixel of a modified IPStype liquid crystal display device for schematically explaining anessential part of the pixel constitution of the forty-fifth embodimentof the present invention and FIG. 72 is a cross-sectional view takenalong a line XI-XI in FIG. 71. In this embodiment, the liquid crystaldisplay device is provided with a reference/counter electrode layerST/CT which functions as a reference electrode layer and also as acounter electrode and a portion of an organic insulation layer O-PAS ina pixel region is removed.

FIG. 73 is a cross-sectional view taken along a line XI-XI in FIG. 71 ofthe vicinity of one pixel of a modified IPS type liquid crystal displaydevice for schematically explaining an essential part of the pixelconstitution of the forty-sixth embodiment of the present invention. Inthis embodiment, a counter electrode CT is formed over an organicinsulation layer O-PAS and a portion of the organic insulation layerO-PAS within a pixel region is removed.

Due to the constitutions of the forty-fifth embodiment and theforty-sixth embodiment, it is possible to form a plurality of regionswhich differ in driving voltage within the pixel region so that theliquid crystal display device can obtain a multi-domain effect.

FIG. 74 is a plan view of the vicinity of one pixel of another modifiedIPS type liquid crystal display device for schematically explaining anessential part of the pixel constitution of the forty-seventh embodimentof the present invention and FIG. 75 is a cross-sectional view takenalong a line XII-XII in FIG. 74.

In this embodiment, the liquid crystal display device is constituted asfollows. That is, liquid crystal is filled in a gap which is defined bya first substrate SUB1 and a second substrate SUB2 which face each otherin an opposed manner. On an inner surface of the first substrate, atleast a plurality of gate lines which extend in the first direction andare arranged in parallel to each other, a plurality of drain lines whichextend in the second direction crossing the gate lines and are arrangedparallel to each other, a plurality of switching element which areprovided to crossing portions of the gate lines and drain lines, pixelelectrode which are driven by the switching elements, and counterelectrodes which generate electric fields for driving pixels between thepixel electrodes and the counter electrodes are formed. Pixel regionsare constituted of a plurality of pixel electrodes.

Further, with respect to the shapes of these electrodes, the pixelelectrode PX may be formed in a planar shape and the counter electrodeCT may be formed in a herringbone shape. That is, in this embodiment,the electrodes may be configured to have shapes opposite to the shapesof electrodes shown in FIG. 60, FIG. 65, FIG. 68 or FIG. 71. In thiscase, it is possible to shield a leaked electric field from the gateline GL and the drain line DL by the counter electrode CT so that thefurther enhancement of image qualities can be realized.

Further, in this embodiment, between the electrode forming layer whichis constituted of the gate line GL, the drain line DL, thin filmtransistor TFT, and the pixel electrode PX including the pixel regionsof the first substrate SUB1 and the first substrate SUB1 side, thereference electrode layer ST which is insulated by the first insulationlayer O-PAS1 with respect to the electrode forming layer is formed.

With respect to the electrode forming layer, over the organic insulationlayer O-PAS1, the gate line GL, the gate insulation layer GI, thepassivation layer PAS, the second organic insulation layer O-PAS2 andthe counter electrode CT are laminated in this order. The counterelectrode layer CT is shared by a pixel region disposed close to thepixel region in the extension direction of the gate line GL and a pixelregion disposed close to the pixel region in the extension direction ofdrain line DL. Then, the counter electrode layer CT is connected to thereference electrode layer ST via a through hole TH which penetrates thesecond organic insulation layer O-PAS2, the passivation layer PAS, thegate insulation layer GI and the first organic insulation layer O-PAS1,thus forming holding capacity of the pixel between the pixel electrodePX and the reference electrode layer ST.

Due to the constitution of this embodiment, it is possible to shieldleaking of electric field from the gate line GL and the drain line DLusing the counter electrode CT and hence, the further enhancement ofimage qualities can be realized.

FIG. 76 is a cross-sectional view taken along a line XII-XII in FIG. 74of the vicinity of one pixel of another modified IPS type liquid crystaldisplay device for schematically explaining an essential part of thepixel constitution of the forty-eighth embodiment of the presentinvention. This embodiment includes a capacitive electrode layer TEDwhich is connected to a reference electrode layer ST via through hole THbelow a pixel electrode PX and is arranged between a first organicinsulation layer O-PAS1 and a gate insulation layer GI.

Due to such a constitution, holding capacity can be increased andadjusted by changing an area of the capacitive electrode layer TED.

FIG. 77 is across-sectional view taken along a line XII-XII in FIG. 74of the vicinity of one pixel of another modified IPS type liquid crystaldisplay device for schematically explaining an essential part of thepixel constitution of the forty-ninth embodiment of the presentinvention. In this embodiment, a portion of a first organic insulationlayer O-PAS1 which forms holding capacity below a pixel electrode PX isremoved.

In such a constitution, due to devoid of the organic insulation layerhaving small dielectric constant, the holding capacity formed betweenthe pixel electrode PX and the reference electrode layer ST can beincreased.

FIG. 78 is across-sectional view taken along a line XII-XII in FIG. 74of the vicinity of one pixel of another modified IPS type liquid crystaldisplay device for schematically explaining an essential part of thepixel constitution of the fiftieth embodiment of the present invention.In this embodiment, a portion of a second organic insulation layerO-PAS2 which is disposed above a pixel electrode PX and below a counterelectrode CT is removed.

Also in this embodiment, due to devoid of the organic insulation layerhaving small dielectric constant, the holding capacity formed betweenthe pixel electrode PX and the reference electrode layer ST can beincreased.

FIG. 79 is a cross-sectional view taken along a line XII-XII in FIG. 74of the vicinity of one pixel of another modified IPS type liquid crystaldisplay device for schematically explaining an essential part of thepixel constitution of the fifty-first embodiment of the presentinvention. In this embodiment, a capacitive electrode layer TED isformed between a gate insulation layer GI and a first organic insulationlayer O-PAS1 which are disposed below a pixel electrode PX. Thiscapacitive electrode layer TED is connected to a counter electrode layerCT at a position not shown in the drawing. Further, the capacitiveelectrode TED may be formed parallel to the extension direction of thegate line GL and is shared in common by the pixels.

Due to such a constitution, the holding capacity can be increased oradjusted by changing an area of the capacitive electrode TED.

Embodiments of other constitutional portions of the liquid crystaldisplay device of the present invention are explained hereinafter.

FIG. 80 is an explanatory view of the substrate constitution of theliquid crystal display device of the present invention. The liquidcrystal display device PNL is constituted by laminating the firstsubstrate SUB1 and the second substrate SUB2 having a size smaller thanthat of the first substrate SUB1 to each other by way of the liquidcrystal. On one side of the first substrate SUB1 and another side of thefirst substrate SUB1 which is disposed close to one side, terminalregions (drain-line-side terminal region TMD, gate-line-side terminalregion TMG) are formed. An effective display region is provided to themost portion of the second substrate SUB2 which is overlapped to thefirst substrate SUB1.

FIG. 81 is an explanatory view showing a state in which a tape carrierpackage loading a driving circuit thereon is mounted on the firstsubstrate SUB1 at the terminal regions. A plurality of tape carrierpackages TCP (tape carrier packages for driving drain lines which loaddrain-line driving circuit chips CH2, tape carrier packages for drivinggate lines which load gate-line driving circuit chips CH1) arerespectively mounted on the drain-line-side terminal region TMD and thegate-line-side terminal region TMG.

FIG. 82 is an explanatory view showing a state in which driving circuitchips are directly mounted on the first substrate SUB1 at the terminalregions. A plurality of drain-line driving circuit chips CH2 are mountedon the drain-line-side terminal region TMD and a plurality of gate-linedriving circuit chips CH1 are mounted on the gate-line-side terminalregion TMG. This mounting method is referred to as a FCA method (or aCPG method).

FIG. 83 is an explanatory view showing an arrangement example of liquidcrystal filling ports through which liquid crystal is filled into a gapdefined by two substrates and is sealed thereafter. In this example, twoliquid crystal filling ports INJ are formed in a side on which thedriving circuit chips are not mounted. The number and mounting positionsof the liquid crystal filling ports INJ are determined corresponding tothe size of the liquid crystal display device PNL and may be one, threeor more.

FIG. 84 is a schematic cross-sectional view of the liquid crystaldisplay device of the present invention. On an inner surface of thefirst substrate SUB1, the reference electrode layer ST is formed and theorganic insulation layer O-PAS is formed over the reference electrodelayer ST. Other layers and electrodes are omitted from the drawing. Theliquid crystal LC is sealed between the first substrate SUB1 and thesecond substrate SUB2 and a periphery of the effective display region issealed by a sealing member.

FIG. 85 is a plan view for schematically explaining the terminal regionsof the gate driving circuit which is mounted in a tape carrier packagemethod. In FIG. 85( a) to FIG. 85 (c), terminals of the driving circuitchip CH1 which are loaded on the tape carrier package TCP are connectedto terminal portions of the gate lines which are pulled out to the firstsubstrate SUB1 side. The connection to the reference electrode ST isperformed by removing the organic insulation layer O-PAS. Portions wherethe organic insulation layer O-Pas is removed are indicated by XP. FIG.85( a) indicates a state in which the removing portions XP are arrangedat the outside of the sealing member SL and below the tape carrierpackage TCP.

FIG. 85 (b) shows a state in which the removing portion XP of theorganic insulation layer O-PAS is disposed at the outside of the sealingmember SL and at positions away from the tape carrier package TCP.Further, FIG. 85( c) shows a state in which the removing portion XP ofthe organic insulation layer O-PAS is arranged at the inside of thesealing member SL.

FIG. 86 is a plan view for schematically explaining the terminal regionon which the driving circuit chip is mounted by a FCA method. FIG. 86(a) indicates a state in which the organic insulation layer O-PAS isremoved at the outside of the sealing member SL and a feeding terminalof the driving circuit chip for the reference electrode layer isconnected at this removing portion XP. FIG. 86 (b) shows a state inwhich the organic insulation layer O-PAS is removed at the inside of theseal member SL and the feeding terminal of the driving circuit chip forthe reference electrode layer is connected at this removing portion XP.It is desirable that a width of a feeding line to the referenceelectrode layer is larger than a width of other signal lines forreducing the feeding resistance.

FIG. 87 is a plan view for schematically explaining the terminal regionwhen a method in which electricity is fed from a reference potentialgeneration circuit disposed in a control circuit of the liquid crystaldisplay device to a using flexible printed circuit board or the like isadopted. A reference electrode feeding line STL is formed on theflexible printed circuit board FPC and electricity is fed to a terminalof the reference electrode which is pulled out to the first substrateSUB1 via the flexible printed circuit board FPC from the referencepotential generation circuit disposed in the control circuit of theliquid crystal display device. FIG. 87( a) shows a case in which thisfeeding method is adopted in the tape carrier package mounting methodand FIG. 87( b) shows a case in which this feeding method is adopted ina FCA method. In this manner, by performing the feeding of electricityto the reference electrode layer ST using the flexible printed circuitboard FPC without going through the driving circuit chip CH1 so that thefeeding of electricity can be performed with the further lower feedingresistance. In the drawing, GDL indicates a feeding line to the gateline.

FIG. 88 is a schematic plan view of the liquid crystal display devicefor explaining the first example for forming the feeding terminal to thereference electrode. In both of the vertical field method and the IPSmethod (including the modified IPS method and other modified IPSmethod), a periphery of the reference electrode ST is patterned thusforming lead terminals STT and feeding of electricity to the referenceelectrode ST is performed using constitutions shown in FIG. 84 to FIG.87.

FIG. 89 is a schematic plan view of the liquid crystal display devicefor explaining a second example for forming feeding terminals to thereference electrode and FIG. 90 is a cross-sectional view of anessential part showing a portion A in FIG. 89 in an enlarged manner.Particularly in the vertical field method having common electrodes atthe second substrate SUB2 side, connection portions STC are formed oncorner portions of the reference electrode ST by patterning and thecommon electrode ST is connected to the reference electrode ST at theconnection portions STC by means of a conductive paste AG. The feedingof electricity to the reference electrode ST is performed by the commonelectrode. It is not always necessary to provide the connection portionSTC at all corner portions of the reference electrode ST and may beformed at one, two or three corner portions of the reference electrodeST.

FIG. 91 is a schematic cross-sectional view of the liquid crystaldisplay device for explaining a third example of the formation of afeeding terminal to the reference electrode and FIG. 92 is across-sectional view of an essential part which shows the feedingterminal portion in FIG. 91 in an enlarged manner. The feeding terminalSTT to the reference electrode ST may be formed separately from theformation of the reference electrode ST. Further, the feeding terminalSTT may be pulled out as a line which is connected with other line suchas the gate line or the drain line at the inside of the seal SL. Here,the connection resistance of both lines are taken into account. Theabove-mentioned constitution is suitable when the contact resistancebetween the feeding terminal STT and the reference electrode ST formedof a transparent electrode made of non-Al-based metal (metal of highmelting point such as Cr, Mo, Ti, Ta, W, Zr or the like, or alloythereof) is low. Here, the feeding terminal STT may be formed of atransparent conductive film (ITO, IZO or the like).

FIG. 93 is a schematic cross-sectional view of a liquid crystal displaydevice for explaining a fourth example of the formation of the feedingterminal to the reference electrode. When the contact resistance betweenthe feeding terminal STT and the reference electrode ST is high, it ispreferable to connect them using an auxiliary connection line STT′. Forexample, when the feeding terminal STT is made of Al, the auxiliaryconnection line STT′ made of non-Al-based metal is used. Further, whenthe auxiliary connection line STT′ is also formed of a transparentconductive film and also when the Al-based feeding terminal STT and thereference electrode ST are directly connected to each other, differentfrom usual signal lines, it is possible to perform the multiple-pointfeeding of electricity and hence, the constitution shown in FIG. 93 isavailable.

FIG. 94 is a schematic cross-sectional view of the liquid crystaldisplay device for explaining a constitutional example of an outerperiphery of an effective display region when the organic insulationlayer formed on the first substrate is formed of a color filter CF. Whenthe organic insulation layer is formed of the color filter CF, the colorfilter material CF1 of three primary colors (R, G, B) or the colorfilter material CF1 formed of at least one of these colors and the colorfilter material CF2 formed of at least other color are laminated to theouter periphery of effective display region. With such a constitution,it is possible to form a light shielding layer on the outer periphery ofthe effective display region. Further, when two color filter materialsare laminated to the outer periphery of the effective display region,one color filter material CF1 is red (R) and the other color filtermaterial CF2 is green (G) or blue (B). The color filter material Rabsorbs light other than red (R) light. Accordingly, by combining colorfilter material G or B which absorb red (R) with the color filtermaterial R, the color filter CF can absorb lights of respective colorsR, G, B.

FIG. 95 is a schematic cross-sectional view of the liquid crystaldisplay device for explaining another constitutional example of theouter periphery of the effective display region when the organicinsulation layer formed on the first substrate is formed of the colorfilter. That is, this example shows a case in which the color filter CF2which is explained in conjunction with FIG. 94 is laminated to thesealing portion SL and an outer peripheral portion thereof. Further, toprotect the whole color filter layer including the color filter layers(CF1, CF2) and the effective display region, it is preferable to form anovercoat layer OC over the color filter layer (CF, CF1, CF2).

FIG. 96 is a schematic cross-sectional view of the liquid crystaldisplay device for explaining a constitutional example in which a colorfilter is formed over all of a sealing portion, an outer peripheralportion thereof and an effective display region. Also in this case, itis preferable to form an overcoat layer OC over the color filter layerCF which covers all of the sealing portion, the outer peripheral portionthereof and the effective display region.

FIG. 97 is an explanatory view of an aligning method in mounting drivingcircuits to various types of lead terminals and feeding terminals formedon a first substrate. FIG. 97( a) shows a case in which a tape carrierpackage is used and FIG. 97( b) shows a case in which a FCA method isadopted. In FIG. 97( a) and FIG. 97( b), when a color filter CF isprovided also outside the sealing member, it is preferable to formremoving portions XP in the color filter CF in the vicinity of alignmentmarks AM for achieving the alignment of a tape carrier package TCP whichmounts a driving circuit chip CH1 thereon or a driving circuit chip CH1of FCA with various types of lead terminals and feeding terminals formedon the first substrate. Due to such a constitution, the generation of anerror at the time of performing the optical recognition of the alignmentmarks AM is prevented so that the mounting accuracy is ensured.

FIG. 98 is a schematic cross-sectional view of a liquid crystal displaydevice which is configured to prevent electrolytic corrosion of areference electrode layer formed on a first substrate. To preventelectrolytic corrosion of the reference electrode layer ST outside asealing member SL, the reference electrode layer ST including endportions thereof is covered with an organic insulation layer O-PAS.

FIG. 99 is a schematic plan view for explaining an example of theformation of a color filter when an organic insulation layer formed on afirst substrate is made of the color filter. As shown in FIG. 99, thecolor filter CF may be formed only at an inner side of a sealing memberSL. The color filter CF contains a large quantity of pigment or dye toperform a function of selecting wavelength of light. Accordingly, thecolor filter CF has a tendency of exhibiting higher hygroscopic propertycompared to a colorless organic insulation layer.

When the color filter CF is disposed in a region outside the sealingmember SL which exhibits high temperature and high humidity, the colorfilter CF in the region absorbs moisture and swells so that wrinkles aregenerated and hence, there is a possibility that lead lines and feedinglines which are formed over the color filter CF are disconnected. Toprevent such a phenomenon, the color filter CF is formed only at theinside of the sealing member SL.

FIG. 100 is a schematic plan view served for explaining an example ofthe formation of a color filter when an organic insulation layer formedon the first substrate is made of the color filter. Compared to theconstitution explained in conjunction with FIG. 99, in this example, thereference electrode layer ST is formed such that the reference electrodelayer ST is extended to the outside of the sealing member SL. Further,in this example, to prevent the short-circuiting between the referenceelectrode layer ST and the scanning signal line or the like, portions ofthe reference electrode layer ST on which the color filter CF is notformed are covered with an overcoat layer OC. Due to such aconstitution, the above-mentioned short-circuiting can be surelyprevented.

FIG. 101 is a schematic plan view served for explaining anotherconstitutional example in which the organic insulation layer formed onthe first substrate is constituted of the color filter. When the colorfilter layer CF is formed only in the inside of the effective displayregion of the first substrate SUB1, the reference electrode layer ST isalso formed only in the inside of the effective display region. Here,the reference electrode layer ST may be stuck out from the color filterCF provided that the reference electrode layer ST does not cross otherlines.

FIG. 102 is a schematic plan view served for explaining still anotherconstitutional example in which the organic insulation layer formed onthe first substrate is constituted of the color filter. Compared to thecase shown in FIG. 101, the reference electrode layer ST is formed suchthat the reference electrode layer ST is stuck out from the color filterCF without crossing other lines in this example as shown in FIG. 102.Further, as shown in FIG. 102, an overcoat layer OC is formed such thatthe overcoat layer OC covers the color filter CF and the referenceelectrode ST.

FIG. 103 is a schematic cross-sectional view for explaining onearrangement example in which the liquid crystal display device of thepresent invention is used as a transmission type display module. On aback surface of the first substrate SUB1 of the liquid crystal displaydevice which is formed by laminating the first substrate SUB1 and thesecond substrate SUB2 to each other, a backlight BL is mounted. Thisarrangement example is a typical constitution of the transmission typedisplay module. Illumination light L1 from the backlight BL is modulatedby the liquid crystal display device when the light L1 passes throughthe liquid crystal display device and is irradiated from the secondsubstrate SUB2 side.

FIG. 104 is a schematic cross-sectional view for explaining anotherarrangement example in which the liquid crystal display device of thepresent invention is used as a transmission type display module. On afront surface of the second substrate SUB2 of the liquid crystal displaydevice which is formed by laminating the first substrate SUB1 and thesecond substrate SUB2 to each other, a front light FL is mounted.Illumination light L1 from the front light FL is modulated by the liquidcrystal display device when the light L1 passes through the liquidcrystal display device and is irradiated from the first substrate SUB1side.

FIG. 105 is a schematic cross-sectional view for explaining the firstarrangement example in which the liquid crystal display device of thepresent invention is used as a reflection type display module. Areference electrode ST which is provided to the first substrate SUB1 ofthe liquid crystal display device which is formed by laminating thefirst substrate SUB1 and the second substrate SUB2 to each other isformed of a reflective metal layer. An external light L2 which isincident on the second substrate SUB2 is reflected on the referenceelectrode ST and the light L2 which is irradiated from the secondsubstrate SUB2 side is modulated in accordance with an electronic latentimage formed in the liquid crystal display device when the light L2passes through the inside of the liquid crystal display device.

FIG. 106 is a schematic cross-sectional view for explaining the secondarrangement example in which the liquid crystal display device of thepresent invention is used as a reflection type display module. On afront surface of the second substrate SUB2 of the liquid crystal displaydevice which is formed by laminating the first substrate SUB1 and thesecond substrate SUB2 to each other, a front light FL is mounted. LightL2 irradiated from the front light FL is reflected on a referenceelectrode ST which is constituted of a reflective metal layer providedto an inner surface of the first substrate SUB1 and is irradiated fromthe second substrate SUB2 side through the front light FL. The light L2is modulated by the liquid crystal display device when the light L2passes through the inside of the liquid crystal display device.

FIG. 107 is a schematic cross-sectiona view for explaining the thirdarrangement example in which the liquid crystal display device of thepresent invention is used as a reflection type display module. On afront surface of the second substrate SUB2 of the liquid crystal displaydevice which is formed by laminating the first substrate SUB1 and thesecond substrate SUB2, a reflection layer RT is mounted. An externallight L2 incident from the first substrate SUB1 is reflected on thereflection layer RT and is irradiated from the first substrate SUB1side. The light L2 is modulated by the liquid crystal display devicewhen the light L2 passes through the inside of the liquid crystaldisplay device.

FIG. 108 is a schematic cross-sectional view for explaining the fourtharrangement example in which the liquid crystal display device of thepresent invention is used as a reflection type display module. A commonelectrode CT which is formed on an inner surface of the second substrateSUB2 of the liquid crystal display device which is formed by laminatingthe first substrate SUB1 and the second substrate SUB2 is constituted ofa reflective metal layer. An external light L2 incident from the firstsubstrate SUB1 is reflected on the common electrode CT and is irradiatedfrom the first substrate SUB1 side. The light L2 is modulated by theliquid crystal display device when the light L2 passes through theinside of the liquid crystal display device.

FIG. 109 is a schematic cross-sectional view for explaining the fiftharrangement example in which the liquid crystal display device of thepresent invention is used as a reflection type display module. On a backsurface of the first substrate SUB1 of the liquid crystal display devicewhich is formed by laminating the first substrate SUB1 and the secondsubstrate SUB2, a front light FL is mounted. Further, a common electrodeCT which is formed on an inner surface of the second substrate SUB2 isconstituted of a reflective metal layer. An external light L2 incidenton the first substrate SUB1 from the front light FL is reflected on thecommon electrode CT and is irradiated from the first substrate SUB1 sideafter passing through the front light FL. The light L2 is modulated bythe liquid crystal display device when the light L2 passes through theinside of the liquid crystal display device.

FIG. 110 is a schematic cross-sectional view for explaining onearrangement example in which the liquid crystal display device of thepresent invention is used as a transmission/reflection type displaymodule. A reference electrode ST which is provided to the firstsubstrate SUB1 of the liquid crystal display device formed by laminatingthe first substrate SUB1 and the second substrate SUB2 is constituted ofa reflective metal layer and includes partial apertures (slit holes ordot holes) corresponding to respective pixels.

When the liquid crystal display device is operated in a reflection typemode, an external light L2 incident from the second substrate SUB2 isreflected on the reference electrode ST and is irradiated from thesecond substrate SUB2. When the liquid crystal display device isoperated in a transmission type mode, light L1 irradiated from thebacklight BL mounted on a back surface of the first substrate SUB1passes through the apertures of the reference electrode ST and isirradiated through the second substrate SUB2. When either one of thelight L2 or the light L1 passes through the inside of the liquid crystaldisplay device, the light L2 or L1 is modulated by the liquid crystaldisplay device. Further, a semitransparent reflection layer may be usedas the reference electrode ST in place of the reflective metal layerhaving apertures. Here, it is needless to say the liquid crystal displaydevice can be operated in both modes, that is, the reflection mode andthe transmission mode.

FIG. 111 is a schematic cross-sectional view for explaining anotherarrangement example in which the liquid crystal display device of thepresent invention is used as a transmission/reflection type displaymodule. A common electrode CT which is provided to the second substrateSUB2 of the liquid crystal display device formed by laminating the firstsubstrate SUB1 and the second substrate SUB2 is constituted of areflective metal layer and includes partial apertures (slit holes or dotholes).

When the liquid crystal display device is operated in a reflection typemode, an external light L2 incident from the first substrate SUB1 isreflected on the common electrode CT and is irradiated from the firstsubstrate SUB1. When the liquid crystal display device is operated in atransmission type mode, light L1 irradiated from the front light FLmounted on a front surface of the second substrate SUB2 passes throughthe apertures of the common electrode CT and is irradiated through thefirst substrate SUB1. When either one of the light L2 or the light L1passes through the inside of the liquid crystal display device, thelight L2 or L1 is modulated by an electronic image formed in the liquidcrystal display device. Further, a semitransparent reflection layer maybe used as the common electrode CT in place of the reflective metallayer having apertures.

The present invention is not limited to the above-mentioned embodimentsand constitutional examples and various liquid crystal display devicescan be constituted using the constitution in which the referenceelectrodes are formed on the substrate side on which the switchingelements such as thin film transistors are formed as the basis.

Further, with respect to the substrates used in the above-mentionedrespective substrates, the substrate SUB1 may be formed of a glasssubstrate.

Alternatively, the substrate SUB1 may be formed of a plastic substrateor a resin substrate.

In the present invention, the reference electrode layer ST is formed inadvance at the time of producing the substrate or before delivering thesubstrate and hence, only the non-defective substrate can be applied sothat the yield rate is enhanced. Further, since it is unnecessary toform the capacity forming portion with high accuracy, the throughput canbe enhanced and the cost can be reduced. Further, the films are formedbefore forming the TFT layer, a manufacturing method such as a coatingmethod which is liable to generate foreign materials can be used andhence, the cost can be further reduced.

Although the structure which is formed by laminating the gate line GL,the gate insulation film GI and the semiconductor layer in this orderhas been explained in the above-mentioned respective embodiments, thestructure may be formed by laminating them in the order of thesemiconductor layer, the gate insulation film GI and the gate line GL.Such a structure is suitable in a case that the semiconductor layer isformed of a layer having crystalline property such as polysilicon, CGS,SLS, SELAX or a layer formed of single crystal.

Further, when the layer having crystalline property is used as thesemiconductor layer, further advantages can be realized. In the presentinvention, between the semiconductor layer and the substrate, thereference electrode layer ST having a large area which extends over thesubstantially whole pixel region is formed. Although the ionimplantation is performed in a step for forming the switching elementusing the semiconductor layer having the crystalline property, ions arewidely implanted covering regions other than the semiconductor layer.According to the present invention, the ion can be shielded with thereference electrode layer ST and hence, it is possible to prevent theion from reaching the substrate SUB1 whereby the substrate SUB1 is notdamaged and the reliability is enhanced.

In the step for forming the semiconductor layer having crystallineproperty, there has been known a method in which after forming anamorphous semiconductor, laser beams are partially irradiated to theamorphous semiconductor to perform scanning so that the semiconductor isfused partially due to heat of laser beams and crystallized to impartthe crystalline property to the semiconductor. For example, SELAX, SLSand the like have been known. In such a method, since heat at a levelwhich can fuse the semiconductor is added to the semiconductor, the heatof high temperature is transmitted to the periphery of the fusedportion. The inventors have found that the strain and thermal stress areaccumulated in the substrate SUB1 due to this heat of high temperature.Further, the inventors of the present invention have found a new problemthat this stress brings about the disturbance in the polarization stateand lowers the contrast ratio.

According to the present invention, the reference electrode layer ST isformed between the semiconductor layer and the substrate SUB1. Since thereference electrode layer ST is broad enough to cover the most portionof the pixel region, extends over a plurality of pixels and isconductive. Accordingly, the local high heat generated by laser beamscan be instantly dispersed so that it is possible to prevent the damageand stress to the above-mentioned substrate and the reduction ofcontrast whereby high quality and high reliability can be realized.

This advantageous effect is an advantageous effect which can be realizedby providing the conductive layer which extends over the substantiallywhole pixel region between the crystalline semiconductor layer and thesubstrate. The present invention also discloses and claims thisconstitution, that is, an image display device having the conductivelayer which extends over the substantially whole pixel region betweenthe crystalline semiconductor layer and the substrate as the presentinvention.

Further, the above-mentioned respective embodiments have been explainedin conjunction with the liquid crystal display device for the sake ofexplanation. However, as can be clearly understood from the explanationof the above-mentioned respective embodiments, with the use of thetechnical concept disclosed by the present invention, the constitutionarranged above the substrate SUB1 can be applicable to an organic EL, aninorganic EL or other image display device. Accordingly, “liquid crystaldisplay device” in the claims discloses and claims the image displaydevice in a range of equivalence. Further, in the same manner,“sandwiching liquid crystal between a first substrate and a secondsubstrate which face each other in an opposed manner” in claims of thisspecification means “a first substrate and a second substrate which arearranged to face each other” in the liquid crystal display device whichconstitutes an equivalent of the liquid crystal display device.

As has been explained heretofore, according to the present invention, byproviding the reference electrode layer functioning as the feedingelectrode which forms holding capacity for activated or lit pixels tothe substrate side on which the switching elements are formed, theresistance to the feeding electrode can be reduced and, at the sametime, the reduction of numerical aperture of the pixels can be obviatedthus realizing the active matrix type liquid crystal display deviceexhibiting high brightness and rapid driving.

Further, it is possible to provide the image display device which cansatisfy both of the assurance of holding capacity and the enhancement ofnumerical aperture.

Still further, it is possible to enhance the image qualities and thereliability of the image display device which uses the crystallinesemiconductor.

1. A liquid crystal display device comprising: liquid crystal sandwichedbetween a first substrate and a second substrate which face each otherin an opposed manner; a plurality of gate lines which extend in thefirst direction and are arranged parallel to each other; a plurality ofdrain lines which extend in the second direction which crosses the gatelines and are arranged parallel to each other; a plurality of pixelregions which are defined among the gate lines and the drain lines; aplurality of switching elements which are arranged at crossing portionsof the gate lines and the drain lines; and pixel electrodes which aredriven by the switching elements are formed on an inner surface of thefirst substrate in the pixel regions, wherein an electrode forming layerincludes the gate lines, the drain lines, the switching elements and thepixel electrodes, a reference electrode layer is formed on the pixelregions and arranged between the first substrate and the electrodeforming layer with a first insulation layer between the referenceelectrode layer and the electrode forming layer, and the electrodeforming layer includes a gate insulation layer, a passivation layer andthe pixel electrode in order over the first insulation layer and furtherincludes a capacitive electrode layer which is connected to the pixelelectrodes, the capacitive electrode layer is formed between the firstinsulation layer and the passivation layer, the capacitive electrodelayer is further formed to not overlap the drain line and the gate line,a second capacitive electrode layer is formed over the first insulationlayer, and the second capacitive electrode layer is connected to thereference electrode layer via through holes which penetrate the firstinsulation layer, and holding capacities of the pixels are formed amongthe pixel electrodes, the reference electrode layer and the capacitiveelectrode layer.
 2. A liquid crystal display device according to claim1, wherein the reference electrode layer is formed on a region of thefirst substrate which includes the gate lines, the drain lines and thepixel electrodes.
 3. A liquid crystal display device according to claim1, wherein the organic insulation layer is formed of color filters.
 4. Aliquid crystal display device according to claim 1, wherein the firstinsulation layer is formed of an organic insulation layer.
 5. A liquidcrystal display device according to claim 1, wherein the liquid crystaldisplay device includes a light shielding layer which performs lightshielding of gaps defined between the drain lines and the pixelelectrodes.
 6. A liquid crystal display device according to claim 1,wherein common electrodes are formed on a side which counters the liquidcrystal of the second substrate.